[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 072345
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED MAR 07 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
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.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N10W 5N20W 1N30W CROSSING THE
EQUATOR AT 40W INTO NE BRAZIL NEAR 1S48W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 3N-5N E OF 20W...AND WITHIN 120-140
NM N OF THE AXIS BETWEEN 40W-47W. SCATTERED MODERATE CONVECTION
IS ALONG THE AXIS BETWEEN 32W-35W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS OVER NE BRAZIL.

...DISCUSSION...

GULF OF MEXICO...
AT 21Z...A 1023 MB SFC HIGH LOCATED OVER SE LOUISIANA EXTENDS A
RIDGE OVER THE ENTIRE GULF AND THE FLORIDA PENINSULA. THIS
FEATURE IS PRODUCING FAIRLY LIGHT WINDS ACROSS THE AREA WITH
SUBSIDING SEAS. LOW LEVEL CLOUDS ARE SEEN OVER THE YUCATAN
PENINSULA AND S MEXICO. IN THE MID AND UPPER LEVELS...THE FLOW
IS MAINLY FROM THE WNW AROUND A RIDGE BUILDING INTO THE GULF
FROM MEXICO. A BAND OF HIGH CLOUDS IS CROSSING CENTRAL MEXICO
AND THE FAR W GULF...BUT OVERALL FAIRLY DRY UPPER AIR DOMINATES.
OVER THE NEXT COUPLE OF DAYS...WEAK RIDGING WILL PERSIST ALONG
THE NRN GULF COAST KEEPING WINDS LIGHT TO MODERATE THROUGH SAT.
SE WINDS WILL INCREASE SAT NIGHT AND SUN AHEAD OF THE NEXT COLD
FRONT THAT IS FORECAST BY THE COMPUTER MODELS TO ENTER THE GULF
ON MON.

CARIBBEAN...
THE TAIL END OF AN OLD FRONTAL BOUNDARY IS GENERATING BROKEN TO
OVERCAST LOW/MID CLOUDS WITH EMBEDDED LIGHT TO MODERATE SHOWERS
OVER E CUBA AND THE BAHAMAS. A WEAK 1016 MB LOW IS IN THE GULF
OF HONDURAS WITH A SFC TROUGH WHICH RUNS FROM 18N85W TO 14N86W.
LOW LEVEL CLOUD MOTION SUGGESTS A WEAK CYCLONIC TURNING OVER THE
AREA. THERE ARE SCATTERED SHOWERS EMBEDDED IN THE ASSOCIATED
BROKEN LOW TO MID CLOUD DECK SEEN ALONG COASTAL HONDURAS AND
BELIZE...AND CARIB WATERS FROM 15N-21N BETWEEN 82W-87W. THE GFS
MODEL INDICATES THAT THIS WEAK AREA OF LOW PRES WILL DRIFT
SLOWLY W OVER THE NEXT COUPLE OF DAYS...WITH SHOWERS LINGERING
BETWEEN HONDURAS...BELIZE...AND THE YUCATAN PENINSULA.
TYPICAL FRAGMENTS OF LOW LEVEL MOISTURE DRIVEN BY THE TRADE
WINDS ARE MOVING ACROSS PUERTO RICO...HISPANIOLA AND JAMAICA.
ELSEWHERE MODERATE TRADES AND FAIR WEATHER ARE DOMINATING.
ALOFT...THE FLOW IS RATHER ZONAL WITH A LARGE AMOUNT OF DRY
STABLE AIR...ESPECIALLY E OF 78W.

WESTERN ATLANTIC...
DEEP LAYER TROUGHING COVERS THE MAJORITY OF THE ATLC W OF 50W
EXTENDING SWD FROM A LARGE POLAR LOW. TWO COLD FRONTS ARE
ASSOCIATED WITH THE TROUGH. ONE OF THEM ENTERS THE AREA NEAR
31N50W AS A STATIONARY FRONT AND EXTENDS SW TO THE CENTRAL
BAHAMAS. THE TAIL END OF THIS FRONTAL SYSTEM IS PRODUCING
BROKEN TO OVERCAST LOW AND MID LEVEL CLOUDS WITH EMBEDDED
SHOWERS OVER THE BAHAMAS AND E CUBA. THIS FRONT IS FORECAST TO
MOVE NWD AS A WEAK LOW TRIES TO DEVELOP IN THE BAHAMAS LATE
THU/FRI. THE SECONDARY AND WEAKER OF THE FRONTS EXTENDS WSW FROM
31N52W TO 27N70W THEN NW TO 29N79W. A THIN ROPE CLOUD HAS BEEN
ASSOCIATED WITH THIS BOUNDARY BUT IS BECOMING RATHER RAGGED.THIS
FRONT WILL DISSIPATE TONIGHT.

EASTERN ATLANTIC...
A 1034 MB HIGH PRES SYSTEM LOCATED MIDWAY BETWEEN THE AZORES AND
THE MADEIRA ISLANDS IS DOMINATING THE SFC PATTERN ACROSS THE
ATLC E OF 45W. THIS HIGH IS PRODUCING MODERATE TO STRONG TRADE
WINDS OF 20 TO 25 KT ACROSS A GOOD PORTION OF THE FORECAST AREA
BUT MAINLY E OF 30W TO THE W COAST OF AFRICA. IN THE UPPER
LEVELS... A FAIRLY VIGOROUS LOW IS LOCATED NEAR 27N38W. THE
DIFFLUENT PATTERN E OF THE UPPER LOW AND ASSOCIATED TROUGHING IS
GENERATING A FAIR AMOUNT OF MOISTURE FROM 10N TO BEYOND 30N
BETWEEN 24-37W. MODELS SHOW THE UPPER LOW MOVING NWD AND OPENING
INTO A TROUGH THROUGH TOMORROW. THIS WILL LIKELY REDUCE THE
AMOUNT OF MOISTURE ACROSS THE REGION AS AN UPPER RIDGE
ESTABLISHES OVER THE FAR E ATLC.

$$
GR




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