[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 302338
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON APR 30 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 3N25W 2N35W...CROSSING THE
EQUATOR NEAR 43W INTO NE BRAZIL. CLUSTERS OF MODERATE TO STRONG
CONVECTION ARE FROM 1N-6N BETWEEN 16W-22W. SIMILAR CONVECTION IS
OVER LIBERIA AND SIERRA LEONE IN AFRICA AND ACROSS NE BRAZIL.
SCATTERED SHOWERS AND ISOLATED TSTMS ARE ELSEWHERE.

...DISCUSSION...

GULF OF MEXICO...
WEAK SFC RIDGING REMAINS IN CONTROL OF THE WEATHER PATTERN
ACROSS THE GULF WATERS THIS EVENING WITH A 1019MB HIGH PRES
CENTER NEAR 28N89W. THIS FEATURE IS PRODUCING MOSTLY CLEAR
SKIES...LIGHT TO MODERATE WINDS...AND SEAS MOSTLY BELOW 4 FT
ACROSS THE AREA. AS WAS THE CASE YESTERDAY...SAT IMAGERY SHOWS
SOME CLOUDINESS IN THE FAR WRN GULF WITH LOW LEVEL SE FLOW.
THESE WINDS ARE TRANSPORTING A HUMID AND UNSTABLE AIRMASS INTO
TEXAS. AS A RESULT...A CLUSTER OF MODERATE TO ISOLATED STRONG
CONVECTION HAS DEVELOPED OVER SE TEXAS WITH THE POTENTIAL OF
SEVERE WEATHER CONDITIONS. ALOFT...A SHORTWAVE TROUGH IS
ENTERING THE W GULF. THE BASE OF THIS TROUGH REACHES CENTRAL
MEXICO WHERE THERE ARE SOME CONVECTIVE ACTIVITY. THIS UPPER
TROUGH WILL BE EXTENDED ACROSS THE CENTRAL GULF AND THE YUCATAN
PENINSULA TOMORROW EVENING. WV IMAGERY SHOWS VERY DRY OVER THE
ERN GULF AND THE FLORIDA PENINSULA. SFC HIGH PRES OVER THE N
GULF WILL SLIDE E OVER THE NEXT COUPLE OF DAYS...ALLOWING THE
RETURN FLOW TO INCREASE IN THE WRN PORTION OF THE GULF.

CARIBBEAN SEA...
LIGHT STREAMER SHOWERS OR CLOUD LINES HAVE DEVELOPED ACROSS THE
WINDWARD/LEEWARD ISLANDS UNDER THE TRADE WIND FLOW. THE SAN JUAN
DOPPLER RADAR IS DETECTING SCATTERED SHOWERS AND ISOLATED TSTMS
OVER PUERTO RICO...THE US/UK VIRGIN ISLANDS AND THE REGIONAL
COASTAL WATERS. PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE
PREVAILING MODERATE TO FRESH TRADE WIND FLOW WILL CONTINUE TO
AFFECT THOSE ISLANDS FROM TIME TO TIME. A SFC TROUGH FROM THE
ATLC EXTENDS OVER THE E BAHAMAS/CUBA AND IS GENERATING SCATTERED
SHOWERS/ISOLATED TSTMS. ANOTHER SFC TROUGH GOES FROM THE CAYMAN
ISLANDS TO THE ATLC COST OF NICARAGUA. THIS FEATURE IS ALSO
PRODUCING AN AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS VERY
CLOSE TO CABO GRACIAS A DIOS. IN THE UPPER LEVELS...GENERALLY
WLY ZONAL FLOW DOMINATES THE BASIN WITH A FLAT RIDGE EXTENDING E
TO W OVER NORTHERN SOUTH AMERICA/CENTRAL AMERICA. HIGH PRES N OF
THE AREA WILL KEEP SIMILAR TRADE WIND REGIME DURING THE NEXT FEW
DAYS.

ATLANTIC...
WEAK SFC HIGH PRES IS BUILDING INTO THE THE WRN ATLC BEHIND THE
SFC TROUGH...REMNANT OF A FRONTAL TROUGH THAT ENTERS THE AREA
NEAR 30N60W AND CONTINUES SW TO THE E BAHAMAS/CUBA NEAR 20N77W.
SCATTERED SHOWERS/ISOLATED TSTMS ARE WITHIN 60NM EITHER SIDE OF
THE SFC TROUGH. ONCE AGAIN...VISIBLE IMAGERY ALSO CONTINUES TO
SHOW THE SMOKE DISPERSING THROUGH FLORIDA AND THE WRN ATLC
ASSOCIATED WITH THE WILDFIRES IN SE GEORGIA. OTHERWISE THE
REMAINDER OF THE ATLC DISCUSSION AREA IS DOMINATED BY THE SRN
PERIPHERY OF A 1030 MB SFC HIGH LOCATED S OF THE AZORES NEAR
35N32W. THIS IS PRODUCING WIDESPREAD FAIR WEATHER AND MODERATE
TO FRESH TRADES E OF 50W. WEAK HIGH PRESSURE WILL CONTINUE TO
BUILD INTO THE WRN ATLC WHILE STRONGER/LARGER HIGH PRESSURE
REMAINS IN CONTROL OF THE E-CENTRAL ATLC. WEAK CONFLUENCE
BETWEEN THESE TWO HIGHS IS SUPPORTING THE AFOREMENTIONED SFC
TROUGH THAT IS FORECAST TO GRADUALLY DISSIPATE.

$$
GR




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