[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 062329
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU MAR 06 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...THE ITCZ...

ITCZ AXIS IS CENTERED ALONG 5N8W 2N17W 1N30W CROSSING THE
EQUATOR NEAR 35W TO 2S43W. SCATTERED MODERATE CONVECTION IS NEAR
THE COAST OF SOUTH AMERICA FROM 1N-5N W OF 46W. ISOLATED
MODERATE CONVECTION IS WITHIN 240 NM OF THE AXIS BETWEEN 26W-38W
AND E OF 14W.

...DISCUSSION...

THE GULF OF MEXICO...

A WELL DEFINED WARM FRONT EXTENDS FROM SOUTH CENTRAL FLORIDA TO
THE W GULF ALONG 26N/27N E OF 94W. THE COMBINATION OF LOW-LEVEL
CONVERGENCE AND AN UPPER SHORTWAVE ROTATING THROUGH THE E GULF
IS CREATING ACTIVE WEATHER ALONG THE FRONT AND OVER MUCH OF THE
NE GULF. LIGHTNING DATA IS VERY STRIKING CLEARING SHOWING
SCATTERED TO NUMEROUS TSTMS WITHIN 75 NM OF THE BOUNDARY. TSTMS
ARE A LITTLE MORE SPREAD OUT OVER THE FAR NE GULF AND
FLORIDA...DUE TO THE UPPER SHORTWAVE AND LOCAL SEABREEZE
INFLUENCES. THE OTHER BIG STORY IS OVER TEXAS AND THE FAR NW
GULF WATERS. THIS IS ASSOCIATED WITH A POTENT COLD FRONT WHICH
IS RIGHT ALONG THE TEXAS COAST AT THE MOMENT. VERY CONTRASTING
WEATHER OVER THE STATE OF TEXAS AS A SNOW STORM IS AFFECTING THE
DALLAS AREA BEHIND THE FRONT AND TEMPS ARE IN THE LOW 90'S F SE
OF THE FRONT JUST W OF A NEWLY FORMED DRY LINE. GALE FORCE WINDS
ARE EXPECTED BEHIND THE FRONT FOR THE WRN AND MIDDLE GULF WATERS.

THE CARIBBEAN SEA...

LARGE MID TO UPPER HIGH DOMINATES THE REGION EXCEPT FOR THE
FAR E PORTION WHERE UPPER TROUGHING IS INDUCED BY A LARGE CUT
OFF LOW IN THE CENTRAL ATLC. WIDESPREAD SUBSIDENCE IS ASSOCIATED
WITH THESE UPPER SYSTEMS EXCEPT FOR PATCHY CIRRUS S OF 12N.
THIS FAIRLY STABLE ENVIRONMENT ALOFT IS CAPPING THE TYPICAL
LOW-LEVEL CLOUD PATCHES...WHICH ARE MOST ORGANIZED IN BANDS OVER
THE NRN LEEWARD ISLANDS AND THE E CARIB MOVING IN FROM THE
ATLANTIC. QUICK MOVING SCATTERED SHOWERS AND LOW TOPPED TSTMS
ARE POSSIBLE IN THESE BANDS. TRADE WINDS ARE MODERATE
TODAY...SLIGHTLY WEAKER THAN THE PAST FEW DAYS. THE NEXT
SIGNIFICANT WEATHER CHANGE IS EXPECTED TO AFFECT THE NW CORNER
ON SAT WHEN A COLD FRONT ENTERS THE REGION.

THE ATLANTIC OCEAN....

A WEAKENING STALLED FRONT EXTENDS FROM 32N76W TO CENTRAL FLORIDA
THEN CONTINUING WWD IN THE GULF. A WEAK UPPER SHORTWAVE ALONG
72W N OF 27N IS ENHANCING CLOUDINESS AND EMBEDDED SCATTERED
SHOWERS/ISOLATED TSTMS N OF 28N BETWEEN 67W-72W. THE REMAINDER
OF THE ATLC PORTION OF THE FRONT APPEARS FAIRLY INACTIVE...BUT
IT IS QUITE DIFFERENT OVER FLORIDA AND THE GULF WATERS. REFER TO
THE GULF OF MEXICO SECTION ABOVE FOR MORE DETAILS. AMPLIFIED
DEEP LAYER HIGH PRES REMAINS IN CONTROL E OF THE
SHORTWAVE/FRONT. THE SFC CENTER HAS WEAKENED A TAD SINCE
YESTERDAY ANALYZED 1029 MB NEAR 35N53W. THE MID AND UPPER CENTER
HAS BECOME GREATLY STRETCHED DUE TO THE INFLUENCE OF TROUGHING
BOTH TO THE E AND W.

THE MAIN FEATURE IN THE E ATLC IS A 1006 MB LOW SPINNING NEAR
28N37W. THIS DEEP LAYER LOW IS CUT OFF FROM THE PROGRESSIVE
PATTERN ALLOWING IT TO BE QUASI-STATIONARY. SCATTERED SHOWERS
AND TSTMS ARE MOST ORGANIZED N OF THE LOW FROM 30N-32N BETWEEN
34W-38W. THIS LOW APPEARS OCCLUDED IN NATURE SO WILL LIKELY
REPRESENT THAT WITH AN OCCLUDED FRONT WRAPPING AROUND THE LOW
TRANSITIONING TO A COLD FRONT FROM 28N35W TO 24N46W. SCATTERED
SHOWERS ARE POSSIBLE WITHIN 120 NM E OF THE FRONT AND ELSEWHERE
WITHIN 240 NM OF THE LOW. GALE CONDITIONS ARE STILL OCCURRING TO
THE W OF THE LOW DUE TO THE TIGHT PRES GRADIENT BETWEEN IT AND
THE 1029 MB HIGH TO THE W. UPPER SWLY FLOW OVER THE REMAINDER OF
THE TROPICAL/SUBTROPICAL E ATLC IS ADVECTING PATCHY HIGH LEVEL
CLOUDS BUT OVERALL LITTLE SIGNIFICANT WEATHER. CONVECTION IN THE
ITCZ IS CONSIDERABLY SUBDUED TODAY COMPARED TO THE PAST COUPLE
OF DAYS.

$$
CANGIALOSI


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