[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 101805 RRA
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SAT MAR 10 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1730 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N12W 2N25W EQ42W AND INTO NE BRAZIL
NEAR 1S51W. ISOLATED CLUSTERS OF MODERATE CONVECTION ARE WITHIN
90 NM N AND 150 NM S OF THE AXIS E OF 21W. SCATTERED MODERATE IS
WITHIN 210 NM N AND 90 NM S OF AXIS BETWEEN 30W-51W.

...DISCUSSION...

GULF OF MEXICO...
WEAK SFC HIGH PRES RIDGING CONTINUES TO DOMINATE MUCH OF THE
GULF...EXTENDING SW FROM THE 1035 MB CENTER PUSHING AWAY FROM
THE MID ATLANTIC COAST. A WEAK TROUGH IS EMBEDDED IN THE RIDGE
IN THE MIDDLE GULF WATERS S OF MISSISSIPPI...ALONG 29N88W
25N89W. SCATTERED LOW TO MID CLOUDS WITH POSSIBLE EMBEDDED LIGHT
RAIN SHOWERS ARE WITHIN 120 NM E OF THE TROUGH AXIS. SIMILAR
CLOUDS ARE IN THE SW GULF/BAY OF CAMPECHE S OF 25N. IN THE UPPER
LEVELS...STRONG ZONAL FLOW DOMINATES MUCH OF THE BASIN BETWEEN
RIDGING EXTENDING N FROM NICARAGUA AND A SHORTWAVE TROUGH
PUSHING THROUGH THE ERN U.S. THE EXCEPTION IS NW FLOW OFF E
TEXAS AND LOUISIANA WHICH IS ADVECTING EXTREMELY DRY UPPER AIR
INTO THE ADJACENT GULF WATERS N OF 27N. THIS IS HELPING SUPPORT
THE CLEAR SKIES/GOOD WEATHER BEING OBSERVED IN THE NW GULF. A
BAND OF UPPER MOISTURE FROM THE EPAC CONTINUES TO SPREAD E
THROUGH THE SRN GULF S OF 25N. OVER THE NEXT COUPLE OF
DAYS...THE WEAK TROUGH WILL GRADUALLY DISSIPATE AS STRONG HIGH
PRES BUILDS N OF THE REGION. THE PRES GRADIENT ON THE S SIDE OF
THE HIGH WILL INCREASE THE SFC EASTERLIES SLIGHTLY ON SUN AND
INTO EARLY NEXT WEEK.

CARIBBEAN...
QUIET WEATHER PERSISTS ACROSS MUCH OF THE BASIN THIS AFTERNOON
WITH PLENTY OF DRY STABLE AIR ALOFT AND MODERATE TRADEWINDS IN
PLACE. UPPER RIDGING GENERALLY DOMINATES THE REGION AS THE
SHORTWAVE TROUGH HAS NOW PULLED E INTO THE CENTRAL ATLC.
ABUNDANT FAIR WEATHER AND TYPICAL ISOLATED TRADE WIND SHOWERS
ARE MOVING WWD ACROSS THE REGION. A MORE CONCENTRATED REGION OF
LOW LEVEL MOISTURE IS NOTED ALONG COASTAL COSTA RICA AND
PANAMA...ASSOCIATED WITH ONSHORE/UPSLOPE FLOW. TRANQUIL WEATHER
IS EXPECTED TO CONTINUE THROUGH THE WEEKEND WITH CONDITIONS
DOMINATED BY MODERATE TO FRESH TRADE WINDS.

WESTERN ATLANTIC...
A LARGE AREA OF MULTILAYER CLOUDINESS AND SCATTERED
SHOWERS/TSTMS CONTINUE TO AFFECT THE REGION. THE STRONGEST
CLUSTER OF MODERATE CONVECTION IS FROM 26N-29N BETWEEN 66W-71W.
CLEAR UPPER DIFFLUENT FLOW IS HELPING SUPPORT THIS CONVECTION.
THE SFC PATTERN CONTRIBUTING TO THIS UNSETTLED WEATHER REMAINS
SOMEWHAT COMPLEX. A 1012 MB SFC LOW IS NEAR 27N72W THAT HAS A
TROUGH EXTENDING S TO THE SE BAHAMAS NEAR 21N74W. A STATIONARY
FRONT EXTENDS ENE FROM THE SURFACE LOW TO NEAR 31N49W. THIS
AFTERNOONS SATELLITE IMAGERY SUGGESTS THERE MAY BE MORE THAN ONE
WAVE OF LOW PRESSURE IN THIS AREA E OF THE BAHAMAS...SO WILL
HAVE TO REEVALUATE FOR THE 1800 UTC MAP. THE MAIN LOW IS
EXPECTED TO MOVE NE THROUGH TONIGHT WHILE INTERACTING WITH
STRONG HIGH PRESSURE TO ITS NE. THIS WILL GENERATE GALE
CONDITIONS ESPECIALLY N AND E OF THE LOW...IN ADDITION TO A
PERSISTENT MODERATE ELY SWELL EVENT FOR THE SE U.S. COAST
THROUGH EARLY NEXT WEEK.

EASTERN ATLANTIC...
STRONG HIGH PRESSURE RIDGING CONTINUES TO DOMINATE THE SFC
PATTERN ACROSS THE ATLC E OF 45W. THIS HIGH IS PRODUCING
MODERATE TO STRONG TRADE WINDS AND FAIR ACROSS A GOOD PORTION OF
THE AREA. IN THE MID AND UPPER LEVELS...STRONG RIDGING ALSO
DOMINATES WITH A HIGH CENTER SEEN SPINNING IN WV IMAGERY NEAR
18N31W. ABUNDANT DRY SUBSIDENT FLOW ALOFT IS WIDESPREAD AIDING
IN THE FAIR WEATHER ACROSS THIS REGION. OVER THE NEXT FEW
DAYS...TRADES WILL RELAX SLIGHTLY THROUGH EARLY TOMORROW AS HIGH
PRES MOVES NE. HOWEVER THEY ARE SET TO PICK UP AGAIN FROM W TO E
LATER SUN AND INTO NEXT WEEK AS STRONG HIGH PRES REBUILDS E
ACROSS THE ATLC OCEAN.

$$
WILLIS





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