[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192314
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT 19 MAR 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2245 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 3N20W 3N30W 1N40W EQ50W.
SCATTERED MODERATE N OF 3N BETWEEN 6W-12W.  ISOLATED MODERATE
WITHIN 60 NM OF AXIS BETWEEN 15W-30W AND S OF 3N W OF 35W.

...DISCUSSION...

GULF OF MEXICO...
QUIET WEATHER WITH A WEAK SURFACE RIDGE OVER THE GULF COURTESY
OF A 1021 MB HIGH OVER SW GEORGIA.  GENERALLY COOL/DRY
CONDITIONS PREVAIL...THOUGH...OVER THE W GULF...SLY RETURN FLOW
CONTINUES TO PRODUCE PATCHY AREAS OF LOW CLOUDS AND ISOLATED
SHOWERS OFF THE MX/TX COASTS. LOOKING UPSTREAM...YET ANOTHER
POTENT S STREAM SHORTWAVE DISTURBANCE MOVING EWD OVER THE SW USA
AND N MEXICO WILL BE THE NEXT WEATHER MAKER AS IT MOVES INTO THE
AREA TONIGHT INTO SUN MORNING.  DYNAMICAL MODELS INDICATE
INCREASING CLOUDINESS THROUGH THE REMAINDER OF TODAY OVER THE W
GULF WITH SHOWERS/TSTMS DEVELOPING OFF THE SE TEXAS COAST
TONIGHT. THE SHORTWAVE AND ASSOCIATED SHOWER/TSTM ACTIVITY
SHOULD MOVE INTO THE CENTRAL GULF SUNDAY. THEREAFTER...THE
PROGRESSION OF THE PATTERN BECOMES A LITTLE LESS CERTAIN WITH
SOME DIFFERENCES IN THE NUMERICAL MODELS.  NONETHELESS...
UNSETTLED CONDITIONS APPEAR LIKELY FOR THE NRN GULF THRU MIDWEEK
WITH PERIODS OF RAIN.

CARIBBEAN...
ANOMALOUSLY STRONG MID/UPPER LEVEL RIDGE REMAINS ANCHORED ACROSS
THE AREA EXTENDING EXTENDING E/W ALONG 12N.  THE MORNING
SOUNDING FROM TRINIDAD HAD ELY WINDS UP THRU 200 MB... FAIRLY
UNUSUALLY FOR THIS TIME OF YEAR AS THE AVERAGE 500 MB WINDS ARE
WLY AT 50 KT.  A BIT OF UPPER LEVEL MOISTURE IS MOVING AROUND
THE W PERIPHERY OF THE RIDGE OVER CENTRAL AMERICA AND THE W
CARIBBEAN BUT MOST OF THE AREA CONTINUES TO BE DOMINATED BY
STRONG SUBSIDENCE PRODUCING DRY/STABLE CONDITIONS ALOFT.  THE
LOWER LEVELS OF THE ATMOSPHERE ARE ALSO RATHER DRY...LIMITING
SHOWER ACTIVITY EXCEPT SOME ISOLATED ACTIVITY ALONG A REMNANT
STATIONARY FRONT FROM THE E TIP OF CUBA TO NE HONDURAS.  THE
BULK OF THIS ACTIVITY IS FOCUSED NEAR THE SW EXTENT OF THE
BOUNDARY OVER HONDURAS.  THE BIG UPPER RIDGE WILL KEEP ANY
SIGNIFICANT SYNOPTIC WEATHER SYSTEM OUT OF THE AREA FOR THE
FORESEEABLE FUTURE.

ATLANTIC...
STRONG MID-LATITUDE WLY FLOW HAS SQUASHED THE TYPICAL ATLC
SUBTROPICAL RIDGE WELL SOUTH INTO THE AREA... FROM THE CANARY
ISLANDS TO A 1018 MB HIGH NEAR 20N45W W TO 21N63W.  DRY ZONAL
UPPER FLOW IS N OF THE RIDGE WITH A WEAK TROF CLIPPING THE AREA
E OF BERMUDA.  ATTENDANT COLD FRONT EXTENDS SWD FROM A 998 MB
SFC LOW N OF THE AREA NEAR 34N41W SW ALONG 25N64W THEN
DISSIPATING STATIONARY TO THE E TIP OF CUBA.  UPPER LEVEL
DYNAMICS ARE NIL WITH THIS SYSTEM AS LOW LEVEL MOISTURE POOLING
IS PRODUCING A NARROW BAND OF SCATTERED SHOWERS EXTEND UP TO 120
NM SE OF THE COLD FRONT AND WITHIN 30 NM EITHER SIDE OF THE
DISSIPATING STATIONARY FRONT. BEHIND THE FRONT...SKIES ARE CLEAR
TO PARTLY CLOUDY TO THE SE UNITED STATES COAST EXCEPT WHERE A
1012 MB LOW OFF THE SOUTH CAROLINA COAST IS PRODUCING SCATTERED
SHOWERS N OF 30N W OF 70W. SCATTERED TO BROKEN HIGH CLOUDINESS
IS N OF 20N E OF 25W THOUGH THESE CLOUDS ARE PRECIPITATION-
FREE.  FARTHER S...MODERATE SUBSIDENCE IN THE UPPER LEVELS AND
DRY AIR IN THE LOWER LEVELS MOVING OFF W AFRICA IS LARGELY
SUPPRESSING CLOUDS IN THE TROPICAL ATLC N OF 10N WHILE UPPER
RIDGING/ DIVERGENCE OVER THE ITCZ IS LEADING TO INCREASED SHOWER
ACTIVITY.

$$
BLAKE





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