[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040537
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SUN MAR 04 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 5N10W 4N25W 1N40W 1N52W. CLUSTERS OF
SCATTERED MODERATE CONVECTION ARE WITHIN 60-100 NM N OF THE
AXIS BETWEEN 15W-32W. WIDELY SCATTERED CONVECTION IS S OF 4N W
OF 32W TO THE COAST OF SOUTH AMERICA.

...DISCUSSION...

GULF OF MEXICO...
BROAD POSITIVELY TILTED MID-UPPER LEVEL TROUGH DOMINATES THE
PATTERN OVER EASTERN NORTH AMERICA WITH MAIN AXIS FROM QUEBEC
SOUTHWESTWARD TO THE MID MISSISSIPPI RIVER VALLEY TO THE TEXAS
PANHANDLE. THIS TROUGH IS INCREASING THE ZONAL FLOW ACROSS THE
NORTHERN GULF STATES AND THE GULF ITSELF...AS A RESULT A VERY
STRONG 160-180 KT SUBTROPICAL JTST IS RACING ACROSS THE DEEP
SOUTH INTO THE CAROLINAS AND W ATLC. DRY AIR/STRONG SUBSIDENCE
IS NOTED OVER THE GULF S OF THE STRONG JET/27N. AT THE SURFACE
BUILDING HIGH PRESSURE OVER THE INTERMOUNTAIN WEST INTO TEXAS IS
BEGINNING TO PUSH A COLD FRONT SLOWLY SWD. AT 03Z...THIS FRONT
LIES ACROSS SOUTH FLORIDA THROUGH 25N85W TO THE YUCATAN
PENINSULA. REGIONAL RADAR MOSAICS IS INDICATING SCATTERED
SHOWERS N OF THE FRONTAL BOUNDARY OVER FLORIDA. HIGH PRESSURE IS
EXPECTED TO BUILD FURTHER INTO THE W GULF THROUGH SUNDAY WITH
STRONG NORTHERLY WINDS INCREASING TO GALE FORCE OVER THE SW GULF
BY SUNDAY AFTERNOON. NLY WINDS OF 20 TO 25 KT ARE ALREADY
BLOWING ACROSS THE W GULF BEHIND THE FRONT. BROKEN TO OVERCAST
LOW LEVEL CLOUDS ARE BANKED UP ALONG THE E SLOPE OF THE SIERRA
MADRE MOUNTAINS.

CARIBBEAN...
EXPANSIVE MID/UPPER LEVEL HIGH IS CENTERED OVER THE NORTHERN
CARIBBEAN NEAR 18N83W WITH THE ASSOCIATED RIDGE AXIS EXTENDING
ENE ACROSS CUBA INTO THE SW ATLC. THIS FEATURE ENCOMPASSES THE
ENTIRE CARIBBEAN AND IS ACCOMPANIED BY VERY STRONG SUBSIDENCE
/DRY AIR ESPECIALLY OVER THE FAR E CARIBBEAN IN THE VICINITY OF
AN UPPER LEVEL TROUGH/SHEAR AXIS WHICH IS UNDERCUTTING THE RIDGE
AXIS AND EXTENDS THROUGH 16N61W TO 13N75W. PRESSURE GRADIENT
BETWEEN THE SURFACE RIDGE OVER THE ATLC AND THE LOW PRESSURE
OVER THE TROPICS INTO THE E PACIFIC REGION IS GENERATING STRONG
EASTERLY TRADE WINDS ACROSS THE AREA WHICH ARE USHERING IN SOME
ISOLATED WARM TOP SHOWERS ACROSS THE REGION...PARTICULARLY
ACROSS THE E CARIBBEAN.

ATLANTIC...
STRONG ZONAL FLOW SOUTH OF THE BROAD TROUGH OVER THE E CONUS IS
SWEEPING OVER THE ATLC N OF 28N W OF 65W. ZONAL FLOW IS
PROVIDING LIMITED SUPPORT FOR A COLD FRONT WHICH EXTENDS FROM
31N70W SOUTHWESTWARD TO THE FLORIDA COAST NEAR FORT LAUDERDALE.
SCATTERED SHOWERS ARE OCCURRING WITHIN 60-90 NM N OF THE
FRONTAL BOUNDARY OVER S-CENTRAL FLORIDA. BROAD UPPER RIDGE
EXTENDS FROM THE CARIBBEAN ACROSS E CUBA INTO THE W AND CENTRAL
ATLC TO BEYOND 32N55W COVERING THE AREA W OF 50W. STRONG
SUBSIDENCE AND VERY DRY UPPER AIR DOMINATE THE REGION S OF 27N W
OF 45W LIMITING SHOWERS ACTIVITY E OF THE W ATLC/GULF COLD
FRONT. A SURFACE RIDGE EXTENDS FROM A 1030 MB HIGH LOCATED NEAR
36N42W SOUTHWEST TO THE CENTRAL BAHAMAS NEAR 24N75W. A MID/UPPER
LEVEL TROUGH EXTENDS THROUGH 32N28W SW ALONG 25N40W TO A
DEVELOPING CYCLONIC CIRCULATION NEAR 18N45W WITH THE ASSOCIATED
COLD FRONT DIPPING INTO THE REGION THROUGH 32N26W TO 26N36W. A
RE-ENFORCING SURGE OF COLD AIR IS JUST N OF THE REGION. A WEAK
SURFACE TROUGH IS IN THE WESTERN TROPICAL ATLC EXTENDING ALONG
56/57W FROM 10N-20N. ONLY ISOLATED LOW TOP SHOWERS ARE OCCURRING
WITH THIS TROUGH.

FAR E TROPICAL ATLC...
A WEAKENING UPPER LOW IS OVER MOROCCO NEAR 28N10W WITH A
MID/UPPER TROUGH EXTENDING SW ALONG THE W COAST OF AFRICA
TO JUST NE OF THE CAPE VERDE ISLANDS WITH MODERATE/STRONG
SUBSIDENCE WITHIN 300 NM OF THE UPPER TROUGH AXIS MAINLY S OF
25N. AN UPPER RIDGE IS OVER THE E TROPICAL ATLC WITH THE CREST
NEAR 22N30W AND IS BUILDING EASTWARD OVER THE AFOREMENTIONED
MID/UPPER TROUGH.

$$
GR/HC




This weather bulletin was brought to you by:
www.nashvilleweather.net