[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 132337
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE MAR 13 2012

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
2330 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL
ATLC TO NEAR 04N12W...WHERE THE ITCZ AXIS CONTINUES THROUGH
02N20W TO S OF THE EQUATOR NEAR 28W INTO SOUTH AMERICA NEAR
01S45W. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE
S OF THE EQUATOR BETWEEN 26W-33W. SCATTERED MODERATE CONVECTION
WAS NOTED ELSEWHERE S OF THE EQUATOR BETWEEN 20W AND 45W...
AND WITHIN 90 NM EITHER SIDE OF THE ITCZ N OF THE EQUATOR BETWEEN
23W AND 26W.

...DISCUSSION...

GULF OF MEXICO...
A PERSISTENT HIGH PRES RIDGE OVER THE GULF COAST EXTENDING ALONG
30N WILL CHANGE VERY LITTLE THROUGH THE END OF THE WEEK. A WEAK
HIGH CENTER IS EXPECTED TO PINCH OFF NEAR PENSACOLA WED AS THE
BERMUDA HIGH SHIFTS EAST. BUOY/CMAN DATA INDICATED E TO SE WINDS
OF 10 TO 15 KT ACROSS THE GULF. SCATTEROMETER DATA SUPPORTED THE
PRESENCE OF THESE WINDS WITH AN 1806 UTC OSCAT PASS INDICATING
HIGHER WINDS OF 20 KT IN THE STRAITS OF FLORIDA. THESE WINDS
WILL CONTINUE ACROSS THE ENTIRE GULF THROUGH THE END OF THE
WEEK. SATELLITE IMAGERY SHOWS A SMALL AREA OF PERSISTENT SHOWERS
AND UNTIL RECENTLY THUNDERSTORM ACTIVITY IN THE SE GULF NEAR
24N88W. THE OSCAT DATA NOTED ABOVE INDICATED LOW LEVEL SPEED
CONVERGENCE FROM WINDS DECELERATING WEST OF THE FLORIDA
STRAITS...WHICH APPEARS TO BE THE PRIMARY FACTOR FOR SHOWERS
REPEATEDLY DEVELOPING IN THAT SAME LOCATION. THE REMAINDER OF
THE GULF HAS MOSTLY CLEAR TO PARTLY CLOUDY SKIES WITH A FEW
ISOLATED SHOWERS.

CARIBBEAN SEA...
THE ASCAT AND OSCAT SCATTEROMETER DATA SETS BOTH MISSED THE CORE
OF THE STRONGEST WINDS WHICH HAVE BEEN OCCURRING ALONG AND
WITHIN 60-90 NM OF THE COAST OF COLOMBIA. HOWEVER NWP MODEL
GUIDANCE FROM GFS AND ECMWF SUGGEST WINDS ALONG THE COAST OF
COLOMBIA SHOULD REMAIN IN THE 25 TO 30 KT RANGE THROUGH THE END
OF THE WEEK. PERSISTENT 1008 MB LOW PRES NEAR 10N75W AND
MODERATE HIGH PRES RIDGE N OF THE AREA ALONG 30N IS ACTING TO
MAINTAIN THIS AREA OF VERY STRONG WINDS IN THE CENTRAL
CARIBBEAN. LITTLE CHANGE TO THE OVERALL SYNOPTIC PATTERN IS
EXPECTED THROUGH SAT. FRESH TRADE WINDS WILL PREVAIL ELSEWHERE
IN THE CARIBBEAN BASIN...WITH HIGHEST WINDS AND SEAS EXPECTED S
OF 18N BETWEEN 68W AND 82W. SATELLITE IMAGERY SHOWS RANDOM
CONVECTION DUE TO TRADE WIND CONVERGENCE OVER MOST OF THE
REGION...AND SMALL CLUSTERS OF MODERATE SHOWERS OVER AND
DOWNWIND OF JAMAICA...WITH AN ADDITIONAL PATCH OF SHOWERS
APPROACHING THE COAST OF NICARAGUA.

ATLANTIC OCEAN...
QUASI-STATIONARY HIGH PRES NEAR 34N61W WILL PERSIST THROUGH WED
NIGHT THEN SHIFT EASTWARD AND WEAKEN AS A COLD FRONT PUSHES OFF
THE EAST COAST OF THE U.S. THU. THE FRONT WILL BRUSH PAST 32N
WITH LITTLE EFFECT IN THE TROPICS THROUGH FRI. 1014 MB GALE
CENTER IS LOCATED JUST NORTH OF THE NEAR 34N41W WITH A COLD
FRONT TRAILING INTO THE AREA NEAR 32N39W AND CONTINUING SW TO
NEAR 23N48W. OSCAT SCATTEROMETER DATA INDICATED NORTHERLY WINDS
OF 30-35 KT NW OF THE LOW WHICH DEFINED THE AREA OF GALES. THE
LOW IS EXPECTED TO REMAIN STATIONARY OVER THE NEXT 24 HOURS AS
IT ENCOUNTERS A STUBBORN BLOCKING HIGH NEAR THE AZORES...WHICH
WILL CAUSE THE LOW TO WEAKEN THROUGH WED EVENING THEN DISSIPATE
INTO A TROUGH ALONG 40W WED NIGHT AND THU. THIN VEIL OF SAHARAN
DUST COVERS A BROAD AREA W-SW OF THE AFRICAN CONTINENT TODAY
FROM THE ITCZ TO 27N E OF 42W...AND IS BECOMING MORE DIFFUSE.
SATELLITE IMAGERY SHOWS RANDOM LIGHT TO MODERATE TRADE WIND
SHOWERS ACROSS MOST OF THE REGION WITH NO ORGANIZED AREAS OF
DEEP CONVECTION.

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

$$
COBB





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