[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 310558
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN MAY 31 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND 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.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 24W MOVING AT 10-15 KT. WHILE WAVE
REMAINS EMBEDDED WITHIN THE ITCZ...A SLIGHT CYCLONIC TURNING OF
THE LOW LEVEL CLOUDS IS EVIDENT NEAR THE WAVE AXIS AROUND 5N ON
SATELLITE IMAGERY. ISOLATED SCATTERED MODERATE CONVECTION IS
FROM 2N-5N BETWEEN 22W-27W.

A TROPICAL WAVE IS ALONG 55W S OF 10N MOVING W AT 10 KT. WAVE
EXHIBITS A FAIRLY WELL DEFINED LOW-LEVEL CLOUD SIGNATURE AND
COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE AS INDICATED BY
THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. AS THIS FEATURE
MOVES ACROSS PORTIONS OF NRN SOUTH AMERICA IT WILL BECOME HARDER
TO DISTINGUISH OVER THE NEXT COUPLE OF DAYS. ISOLATED MODERATE
CONVECTION IS S OF 7N BETWEEN 50W-56W.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 8N13W 5N22W 4N27W 1N40W AND
CONTINUING ALONG THE EQUATOR INTO NE BRAZIL NEAR 50W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 1N-7N BETWEEN
6W-13W. ELSEWHERE...SCATTERED MODERATE CONVECTION IS FOUND
WITHIN 60 NM EITHER SIDE OF A LINE FROM 5N20W 2N37W 4N48W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 0300 UTC...A STATIONARY FRONT EXTENDS FROM THE W ATLC OVER
THE SRN FLORIDA PENINSULA NEAR FORT MYERS ALONG 24N87W 23N93W. A
PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM 24N87W ACROSS THE
WRN YUCATAN PENINSULA TO NEAR 19N91W. THE FRONTAL BOUNDARY ALONG
WITH AN AREA OF UPPER LEVEL DIFFLUENCE MAXIMIZED ACROSS SRN
FLORIDA...WRN CUBA AND THE STRAITS OF FLORIDA IS GENERATING
SCATTERED SHOWERS AND ISOLATED TSTMS S OF 26N E OF 84W INCLUDING
THE EXTREME SRN FLORIDA PENINSULA...FLORIDA KEYS AND STRAITS OF
FLORIDA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE ALSO ACROSS
THE YUCATAN PENINSULA WITHIN 90 NM OF THE SURFACE TROUGH. A WEAK
1016 MB SURFACE HIGH IS LOCATED IN THE N/CENTRAL GULF NEAR
29N91W WITH LIGHT SURFACE WINDS COVERING MUCH OF THE NRN AND WRN
GULF WATERS IN RESPONSE TO THIS FEATURE. AS THIS RIDGE OF HIGH
PRESSURE DRIFTS EWD OVER THE NEXT COUPLE OF DAYS...LIGHT SLY
RETURN FLOW IS FORECAST TO DEVELOP BY MONDAY AS THE NEXT AREA OF
LOW PRESSURE DEVELOPS OVER THE SRN PLAINS.

CARIBBEAN SEA...
A SURFACE TROUGH IS INLAND OVER THE YUCATAN PENINSULA AND IS
GENERATING SCATTERED SHOWERS/ISOLATED TSTMS WITHIN 90 NM OF THE
SURFACE FEATURE THAT ARE DRIFTING EWD OVER THE NW CARIBBEAN FROM
18N-21N W OF 85W. THE AFOREMENTIONED AREA OF UPPER DIFFLUENCE
ACROSS WRN CUBA AND THE FLORIDA STRAITS IS MOVING SCATTERED
SHOWERS AND ISOLATED TSTMS OVER THE TOP OF AN UPPER RIDGE
LOCATED ACROSS CENTRAL AMERICA AND SRN MEXICO SWD ACROSS W CUBA
AND INTO THE COASTAL WATERS N OF 21N BETWEEN 80W-83W. THE ITCZ
CROSSES COSTA RICA AND WRN PANAMA GENERATING SCATTERED MODERATE
CONVECTION MAINLY SW OF A LINE FROM 14N83W TO 9N76W ACROSS THE
SW CARIBBEAN. OTHERWISE THE REMAINDER OF THE CARIBBEAN REMAINS
TRANQUIL WHILE DRIER AIR AND NW FLOW DOMINATES ALOFT. AT THE
SURFACE...MODERATE TO STRONG ELY TRADE WINDS REMAIN DUE TO THE
SURFACE RIDGE ANCHORED OVER THE CENTRAL ATLC AND THE TYPICAL
LOWER PRESSURE OVER SOUTH AMERICA. LOW-LEVEL CONVERGENCE OF
THE TRADE WINDS COULD PRODUCE POSSIBLE ISOLATED SHOWERS ACROSS
THE ERN CARIBBEAN E OF 72W.

ATLANTIC OCEAN...
A 1010 MB LOW IS CENTERED NEAR 31N78W IN THE W ATLC AND EXTENDS
A STATIONARY FRONT TO THE CENTRAL FLORIDA PENINSULA NEAR
MELBOURNE TO FORT MYERS AND INTO THE SE GULF OF MEXICO.
SCATTERED SHOWERS AND ISOLATED TSTMS ARE S OF 30N TO OVER CUBA W
OF 77W ACROSS EXTREME SRN FLORIDA AND THROUGH THE FLORIDA
STRAITS. ALL OF THIS ACTIVITY IS LOCATED UNDER MOIST AND
UNSTABLE SWLY FLOW ALOFT AND AN UPPER DIVERGENT WIND FIELD. A
BROAD UPPER LOW IS OVER THE W/CENTRAL ATLC N OF PUERTO RICO NEAR
22N61W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 28N56W TO
23N59W BUT IS EMBEDDED WITHIN DRIER AIR ALOFT AND ONLY PRODUCING
SHALLOW ISOLATED SHOWERS WITHIN 200 NM E OF THE SURFACE TROUGH.
OVER THE E ATLC...AN UPPER LEVEL TROUGH IS N OF 15N E OF 35W BUT
LACKS ANY SIGNIFICANT CONVECTION OR PRECIPITATION. AT THE
SURFACE...THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE
RIDGE THAT IS ANCHORED BY A 1024 MB HIGH NEAR 29N46W AND IS
BRIDGING A COLD FRONTAL BOUNDARY THAT IS CURRENTLY N OF THE
REGION ALONG 31N. SCATTERED SHOWERS ARE WITHIN 90 NM S OF THE
FRONT BETWEEN 25W-45W.

$$
HUFFMAN





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