[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121749
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO
04N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
04N20W TO 02N37W TO THE EQUATOR NEAR 46W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 02N-04N BETWEEN 27W-45W...AND FROM
THE EQUATOR TO 06N BETWEEN 47W-52W.

...DISCUSSION...

GULF OF MEXICO...
MIDDLE TO UPPER LEVEL TROUGHING IS ASSOCIATED WITH AN UPPER
LEVEL CYCLONIC CIRCULATION CENTERED OVER EASTERN QUEBEC THAT
SUPPORTS A STATIONARY FRONT ANALYZED ACROSS NORTHERN FLORIDA AND
ALONG THE NORTHERN GULF COAST FROM 30N85W TO 29N93W TO THE TEXAS
COAST NEAR BROWNSVILLE AND THEN INLAND ACROSS NORTHEASTERN
MEXICO. MOSAIC DOPPLER RADAR IMAGERY INDICATES ISOLATED SHOWERS
ARE OCCURRING WITHIN 50 NM EITHER SIDE OF THE FRONT AND WELL
NORTH OF THE FRONT OVER INLAND PORTIONS OF THE LOWER MISSISSIPPI
RIVER VALLEY. SOUTH OF THE FRONT...THE WESTERN PERIPHERY OF A
SURFACE RIDGE ANCHORED OVER THE SW NORTH ATLC IS PROVIDING FOR
SOUTHERLY WINDS IN THE RANGE OF 10 TO 20 KT. SKIES REMAIN
GENERALLY CLEAR OVER THE REMAINDER OF THE BASIN WITH CLOUDINESS
INCREASING IN THE VICINITY OF THE FRONT N OF 26N. THE FRONT IS
FORECAST TO LIFT NORTHWARD AS A WARM FRONT LATER TODAY AS
SURFACE LOW PRESSURE DEVELOPS OVER EASTERN TEXAS AND MOVES
EASTWARD ACROSS THE SE CONUS INTO WEDNESDAY. WITH CYCLOGENESIS
ANTICIPATED...THE ASSOCIATED COLD FRONT IS EXPECTED TO EMERGE
OFF THE TEXAS AND LOUISIANA COAST LATE TUESDAY INTO EARLY
WEDNESDAY INTRODUCING NORTHERLY WINDS IN WAKE OF THE FRONT FOR
THE NW AND WEST-CENTRAL PORTIONS OF THE GULF.

CARIBBEAN SEA...
NORTH-NORTHWESTERLY UPPER LEVEL FLOW DOMINATES OVER THE
CARIBBEAN WITH WATER VAPOR IMAGERY INDICATING VERY DRY AIR AND
STRONG SUBSIDENCE KEEPING SKIES FAIR AND CONDITIONS TRANQUIL
ACROSS A MAJORITY OF THE BASIN THIS AFTERNOON. THE EXCEPTION TO
AN OVERALL QUIET DAY IS THE PRESENCE OF A SHEAR LINE ANALYZED
FROM THE CENTRAL ATLC INTO THE CARIBBEAN NEAR 16N62W TO 16N66W
TO 16N71W. THE SHEAR LINE IS PROVIDING FOCUS FOR WIDELY
SCATTERED SHOWERS FROM 14N-18N BETWEEN 58W-75W....INCLUDING A
PORTION OF THE LEEWARD ISLANDS. LOW-LEVEL MOISTURE AND ISOLATED
SHOWERS STRETCH WESTWARD OCCURRING OVER JAMAICA AS WELL FROM
17N-20N BETWEEN 75W-79W. OTHERWISE...TRADES REMAIN BRISK
GENERALLY IN THE RANGE OF 15 TO 25 KT WITH HIGHER SPEEDS
FORECAST IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA. LOOKING
AHEAD...THE SHEAR LINE IS EXPECTED TO CONTINUE SLOWLY DRIFTING
SOUTHWARD AND BECOME DIFFUSE OVER THE NEXT 12 TO 24 HOURS WHILE
CONTINUING TO PROVIDE INCREASED PROBABILITY OF PRECIPITATION
ACROSS THE EASTERN CARIBBEAN.

ATLANTIC OCEAN...
MIDDLE TO UPPER LEVEL RIDGING EXTENDS FROM OVER CENTRAL AMERICA
NEAR 15N90W NORTHEASTWARD TO BEYOND 32N72W IN THE SW NORTH ATLC.
THE RIDGING IS PROVIDING SUPPORT FOR A 1026 MB SURFACE HIGH
CENTERED NEAR 31N56W. FAIR SKIES AND CONDITIONS ARE NOTED N OF
20N W OF 50W IN ASSOCIATION WITH THE HIGH. HOWEVER...THE
NORTHWESTERN PORTION OF THE SW NORTH ATLC IS UNDER THE INFLUENCE
OF A STATIONARY FRONT ANALYZED FROM 32N76W TO THE GEORGIA COAST
NEAR 31N81W. WHILE MOST OF THE CONVECTION IS LOCATED NORTH OF
THE DISCUSSION AREA...ISOLATED SHOWERS ARE OCCURRING N OF 31N
BETWEEN 68W-80W. FARTHER EAST...AN MIDDLE TO UPPER LEVEL TROUGH
WITH AXIS ALONG 42W DIPS SOUTHWARD INTO THE CENTRAL ATLC AND
SUPPORTS A COLD FRONT ANALYZED FROM 32N39W TO 23N47W WHICH THEN
BECOMES A SHEAR LINE TO 17N60W AND INTO THE EASTERN CARIBBEAN
SEA. WIDELY SCATTERED SHOWERS ARE OCCURRING WITHIN 150 NM EITHER
SIDE OF THE COLD FRONT AND WITHIN 120 NM EITHER SIDE OF THE
SHEAR LINE. OTHERWISE THE REMAINDER OF THE EASTERN ATLC IS
DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1032 MB HIGH CENTERED
EAST OF THE AZORES NEAR 38N20W.

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

$$
HUFFMAN




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