[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131705
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1600 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL
ATLC NEAR 07N12W TO 05N14W...WHERE THE ITCZ AXIS CONTINUES TO S
OF THE EQUATOR NEAR 30W INTO SOUTH AMERICA NEAR 03S44W. CLUSTERS
OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE S OF THE
EQUATOR BETWEEN 22W-37W.

...DISCUSSION...

GULF OF MEXICO...
A PERSISTENT HIGH PRES RIDGE OVER THE GULF COAST EXTENDING ALONG
30N WILL CHANGE VERY LITTLE THROUGH THE WEEKEND. A WEAK HIGH IS
EXPECTED TO PINCH OFF NEAR PENSACOLA WED NIGHT AS THE BERMUDA
HIGH SHIFTS EAST. MODERATE E-SE TRADE WINDS WILL CONTINUE ACROSS
THE ENTIRE GULF THROUGH FRI THEN FRESHEN TO AROUND 20 KT W OF 90W
SUN AS A SLOW MOVING TROUGH OF LOW PRESSURE BECOMES ENTRENCHED
OVER THE WESTERN GREAT PLAINS AND FRONT RANGE OF THE ROCKIES.
SATELLITE IMAGERY SHOWS A SMALL AREA OF PERSISTENT SHOWERS IN
THE SE GULF NEAR 24N86W. SCATTEROMETER DATA FROM LAST NIGHT
AROUND 0300 UTC SHOWED LOW LEVEL SPEED CONVERGENCE FROM WINDS
DECELERATING WEST OF THE FLORIDA STRAITS...WHICH APPEARS TO BE
THE PRIMARY FACTOR FOR SHOWERS REPEATEDLY DEVELOPING IN THE SAME
LOCATION. THE REMAINDER OF THE GULF HAS MOSTLY CLEAR TO PARTLY
CLOUDY SKIES WITH FEW SHOWERS.

CARIBBEAN SEA...
SCATTEROMTER DATA AT 0300 UTC LAST NIGHT SHOWED AN AREA OF 30-35
KT WINDS WITHIN ABOUT 75 NM OF THE COAST OF COLOMBIA NEAR 12N74W.
SHIP OBSERVATIONS FROM CRUISE SHIP CELEBRITY EQUINOX CALL SIGN
9HXD9 OVER THE PAST 12 HOURS HAVE ALSO INDICATED GALE FORCE WINDS
WERE PRESENT S OF 13N BETWEEN 73W-77W EARLIER TODAY. THE NEXT
SCATTEROMETER PASSES TODAY MISSED THE AREA OF HIGHEST WINDS...BUT
MODEL GUIDANCE FROM GFS AND ECMWF SUGGEST WINDS ALONG THE COAST
OF COLOMBIA SHOULD DIMINISH SLIGHTLY BY ABOUT 3-5 KT...TO 30 KT
OR LESS BY TONIGHT. 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 CURRENT 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 MOVING DOWNWIND FROM HISPANOLA AND JAMAICA NEAR
17N77W AND 16N77W.

ATLANTIC OCEAN...
QUASI-STATIONARY HIGH PRES NEAR 33N60W WILL PERSIST THROUGH WED
NIGHT THEN SHIFT EASTWARD AS A FRONT PUSHES OFF THE EAST COAST
OF THE U.S. THU. THE FRONT WILL BRUSH PAST 32N WITH LITTLE EFFECT
IN THE TROPICS THROUGH SAT THEN DISSIPATE IN THE CENTRAL ATLC SAT
NIGHT. HIGH PRES WILL REDEVELOP NEAR 33N68W ON FRI AS THE FRONT
SLIDES EAST AND WEAKENS. 1014 MB LOW IS LOCATED NEAR 34N41W WITH
A COLD FRONT TRAILING SW TO 27N46W. SCATTEROMETER DATA SHOWS 20
TO 30 KT SOUTHERLY WINDS N OF 30N ASSOCIATED WITH THIS FEATURE.
THE LOW WILL BECOME STATIONARY OVER THE NEXT 12-24 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.
VERY LITTLE CHANGE TO THE SYNOPTIC PATTERN EXPECTED THROUGH SUN.

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

$$
MUNDELL




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