[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 161741
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI MAY 16 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE
AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING
INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL
ANALYSIS...WEATHER OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 29W S OF 11N MOVING W 15 KT. THE WAVE
REMAINS BROAD IN ITS CLOUD AND MOISTURE STRUCTURE...AS SEEN IN
THE MIMIC TPW ANIMATION. THE AXIS IS PLACED ALONG AN AREA OF
LOW-LEVEL CYCLONIC TURNING AND OVERALL PEAK IN THE LOW-LEVEL
CLOUD MASS. SCATTERED SHOWERS AND TSTMS ARE WITHIN 60 NM W AND
180 NM E OF THE AXIS S OF 8N.

A TROPICAL WAVE IS ALONG THE COAST OF NE BRAZIL NEAR FRENCH
GUIANA ALONG 51W S OF 11N MOVING W 10-15 KT. THIS WAVE IS
DISORGANIZED WITH THE AXIS ALONG THE W EDGE OF ITS ASSOCIATED
CLOUD FIELD...DUE TO ELY SHEAR. VIS IMAGERY DOES SHOW SOME
LOW-LEVEL TURNING CONCENTRATED NEAR 7N. SHOWER AND TSTMS HAVE
DECREASED OVER THE PAST FEW HOURS AND ARE ISOLATED TO SCATTERED
WITHIN 300 NM E OF THE AXIS.

AN ILL-DEFINED TROPICAL WAVE IS OVER COLOMBIA ALONG 76W S OF 12N
MOVING W 10-15 KT. A SMALL BULGE OF MOISTURE ON THE MIMIC TPW
ANIMATION SUGGESTS THE PRESENCE OF THIS WAVE THAT MAY BE
ENHANCING SOME SHOWER ACTIVITY OVER N COLOMBIA. NO OTHER
AVAILABLE DATA PROVIDES GUIDANCE ON THE LOCATION OF THIS
WAVE...SO IT IS MAINLY BASED ON THE TPW ANIMATION AND
EXTRAPOLATION.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N9W 6N20W 5N30W 2N40W 5N50W.
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 1N-5N
BETWEEN 11W-19W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM N
OF THE AXIS BETWEEN 34W-38W.

...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT IS TRACKING SE ACROSS THE GULF ANALYZED FROM
SOUTHERN ALABAMA TO N MEXICO NEAR 25N98W. SFC OBSERVATIONS
SUGGEST A PREFRONTAL TROUGH OVER THE BAY OF CAMPECHE FROM 25N92W
TO 18N94W. LOW-LEVEL LIFT ALONG THE FRONT COMBINED WITH
DIFFLUENT FLOW ALOFT...BETWEEN AN UPPER TROUGH/LOW OVER NW
MEXICO AND AN UPPER HIGH OVER THE NW CARIB AND E GULF...IS
GENERATING SCATTERED TO NUMEROUS SHOWERS AND TSTMS W OF A LINE
FROM N FLORIDA TO THE W PORTION OF THE BAY OF CAMPECHE ALONG
30N83W 19N96W. SAT IMAGERY AND LIGHTNING DATA REVEAL AN
ENHANCEMENT OR DEEPENING ACTIVITY NEAR 27N93.5W. N TO NE WINDS
BEHIND THE FRONT IS ADVECTING A COOLER AIRMASS INTO THE
REGION...BUT IT REMAINS MOIST DUE TO THE ACTIVITY PRODUCED BY
THE DIFFLUENT UPPER FLOW. AHEAD OF THE FRONT...SFC RIDGING IS
HANGING ON WITH ITS ASSOCIATED S TO SW FLOW PROVIDING A WARM AND
HUMID DAY OVER FLORIDA AND THE REMAINDER OF THE GULF WATERS.
THIS FRONT WILL MAKE A LITTLE MORE PROGRESS SE THROUGH TOMORROW
BEFORE BECOMING STATIONARY AND WEAKENING.

CARIBBEAN SEA...
THE TAIL END OF A WEAKENING STATIONARY FRONT EXTENDS TO NEAR THE
VIRGIN ISLANDS. ONLY SCATTERED LOW CLOUDS ARE ALONG THE BOUNDARY
BUT THERE ARE A FEW PATCHES OF SHOWERS ASSOCIATED WITH ITS
REMNANTS OVER PUERTO RICO...THE MONA PASSAGE AND LIKELY OVER S
HISPANIOLA AND JAMAICA. SCATTERED SHOWERS AND TSTMS ARE
APPROACHING THE SRN WINDWARD ISLANDS ASSOCIATED WITH A WEAK
DISTURBANCE MOVING W WITHIN THE ITCZ AND POSSIBLY ENHANCED SOME
BY STRONG SW FLOW ALOFT. OTHERWISE...THE REMAINDER OF THE REGION
IS EXPERIENCING FAIR WEATHER BENEATH A SUBSIDENT ENVIRONMENT
ASSOCIATED WITH A SPRAWLING MID-UPPER RIDGE CENTERED JUST S OF
CUBA AND UPPER TROUGHING OVER THE E CARIB. A QSCAT PASS AROUND
11Z SHOWED 20 KT TRADES CONFINED TO THE CENTRAL PORTION ROUGHLY
BETWEEN COLOMBIA AND HISPANIOLA. SIMILAR MAGNITUDE WINDS ARE
LIKELY IN THE ENHANCED REGION OF THE GULF OF HONDURAS. LITTLE
SIGNIFICANT CHANGE IS EXPECTED IN THIS FLOW REGIME OVER THE NEXT
COUPLE OF DAYS.

ATLANTIC OCEAN...
THE LOW PRES SYSTEM THAT HAS BEEN OVER THE N ATLC MUCH OF THIS
WEEK CONTINUES TO WEAKEN WITH ITS ASSOCIATED COLD FRONT DOING
THE SAME...ENTERING THE REGION NEAR 32N49W TO 22N57W THEN
STATIONARY TO THE VIRGIN ISLANDS. UPPER DIFFLUENCE AND
LOW-LEVEL CONVERGENCE IS PRODUCING SCATTERED SHOWERS AND TSTMS
WITHIN 300 NM E OF THE FRONT N OF 24N. SFC HIGH PRES IS BUILDING
SE BEHIND THE FRONT...ANALYZED 1020 MB NEAR 28N69W. STRONG SW
WINDS HAVE DEVELOPED ON THE W PERIPHERY OF THE HIGH OFF THE
CAROLINA COAST AHEAD OF THE NEXT DEEPENING STORM SYSTEM. A 1025
MB HIGH DOMINATES THE SFC PATTERN E OF THE FRONT CENTERED NEAR
32N37W. THE ONLY INTERRUPTION IN THE SUBTROPICS IS AN E-W TROUGH
LINE ALONG 27N/28N BETWEEN THE CANARY ISLANDS AND 27W. THIS
BOUNDARY IS PRODUCING AN AREA OF CLOUDS AND EMBEDDED SHALLOW
SHOWERS WITHIN 60 NM OF THE AXIS. ALOFT...A RIDGE/TROUGH PATTERN
LIES OVER THE REGION WITH ASSOCIATED UPPER CONFLUENCE PROVIDING
A VERY STABLE ENVIRONMENT FROM 12N-26N E OF 30W.

$$
CANGIALOSI




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