[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 050542
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 05N09W TO
02N15W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
02N15W TO THE EQUATOR NEAR 20W THEN ALONG THE EQUATOR BETWEEN
20W-42W. SCATTERED MODERATE CONVECTION IS FROM 03N-07N BETWEEN
20W-28W. THIS CONVECTION IS LIKELY ENHANCED BY AN UPPER LEVEL
TROUGH AXIS EXTENDING FROM 31N15W TO A BASE NEAR 06N33W.

...DISCUSSION...

GULF OF MEXICO...
SOUTHWESTERLY MIDDLE TO UPPER LEVEL FLOW IS EVIDENT ON WATER
VAPOR IMAGERY OVER MUCH OF THE GULF BASIN THIS EVENING AHEAD OF
A MIDDLE TO UPPER LEVEL LOW CENTERED OVER THE TEXAS AND OKLAHOMA
PANHANDLES. A LINGERING FRONTAL BOUNDARY EXTENDS ACROSS THE
SOUTHERN FLORIDA PENINSULA AND INTO THE GULF AS A STATIONARY
FRONT FROM 26N81W TO 23N86W TO 24N94W TO 20N94W. WHILE THE
APPROACHING UPPER LEVEL LOW AND ASSOCIATED DYNAMICS HAVE A FEW
DAYS TO BEGIN AFFECTING AND SIGNIFICANT MOVEMENT OF THE FRONT...
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. ALSO...A SURFACE TROUGH
EXTENDS FROM THE FRONT NEAR 23N95W NORTHWARD TO THE TEXAS COAST
NEAR 28N96W WHERE CONSIDERABLE CLOUDINESS...SCATTERED SHOWERS...
AND ISOLATED TSTMS ARE OCCURRING FROM 21N-27N BETWEEN 92W-96W.
MOST OF THE MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO STREAM
NORTHEAST FROM THE WESTERN GULF TO THE FLORIDA PANHANDLE AND
INTO THE SW NORTH ATLC WHILE THINNING OUT E OF 78W. STRONG
SURFACE RIDGING TO THE NORTHWEST OF THE FRONT WITH AXIS ALONG
THE MEXICO COAST IS PROVIDING STRONG N-NW WINDS IN THE RANGE OF
20 TO 30 KT WITHIN 90 TO 120 NM OF THE MEXICO COASTLINE.
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 EVENING 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 EXPECTED OFF THE COAST OF COLOMBIA THROUGH
EARLY MONDAY. SATELLITE IMAGERY INDICATES QUICK-MOVING
LOW-TOPPED ISOLATED SHOWERS ARE OCCURRING OVER A BROAD PORTION
OF THE BASIN FROM 12N-18N AND IN THE VICINITY OF THE GULF OF
HONDURAS W OF 86W...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 NEAR 20N68W. MIDDLE TO UPPER
LEVEL MOISTURE CONTINUES TO STREAM NE THEN EASTWARD FROM THE
NORTHERN FLORIDA PENINSULA N OF 28N TO BEYOND 50W. WEAK
MID-LEVEL ENERGY STRETCHES ALONG 35N/36N BETWEEN 40W-65W AND
SUPPORTS A COLD FRONT ANALYZED FROM 32N54W TO 29N65W TO 29N73W.
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 37N76W.
WHILE THE STRONGER DYNAMICS ARE WELL TO THE NORTH OF 32N...A
STATIONARY FRONT CONTINUES TO AMPLIFY SOMEWHAT OVER THE
REMAINDER OF THE SW NORTH ATLC CURRENTLY ANALYZED AS A
STATIONARY FRONT FROM 29N73W TO 29N77W TO THE FLORIDA PENINSULA
NEAR 27N80W. ISOLATED SHOWER ARE OCCURRING N OF 28N BETWEEN
73W-80W. FARTHER EAST...OVER THE CENTRAL AND EASTERN ATLC...A
SURFACE RIDGE DOMINATES ANCHORED BY A 1025 MB HIGH CENTERED NEAR
25N44W. THE RIDGE AXIS REMAINS ROUGHLY ALONG 25N BETWEEN
30W-70W. FINALLY...OVER THE FAR EASTERN ATLC...AN UPPER LEVEL
TROUGH AXIS EXTENDS FROM 31N15W TO A BASE NEAR 06N33W 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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