[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 300557
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT MAY 30 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 49W S OF 9N MOVING W 15-20 KT. TOTAL
PRECIPITABLE WATER PRODUCT FROM CIMSS INDICATES THAT THIS WAVE
COINCIDES WITH AN AREA OF MAXIMUM DEEP LAYER MOISTURE. ALSO...AN
EARLIER SCATTEROMETER PASS AROUND 2130 UTC OBSERVED CYCLONIC
TURNING OF THE WINDS NEAR THE WAVE AXIS. SCATTERED MODERATE
CONVECTION IS S OF 6N BETWEEN 46W-51W.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 7N12W 5N24W CROSSING THE EQUATOR
NEAR 33W EXTENDING TO 2S40W AND INTO NE BRAZIL NEAR 2S45W.
WIDELY SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 8N
BETWEEN 18W-24W. SCATTERED MODERATE CONVECTION IS ALSO S OF 5N
BETWEEN 40W-51W.

...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT IS PRESENT ACROSS THE ERN GULF AND AT 30/0300 UTC
EXTENDS FROM THE BIG BEND REGION OF FLORIDA NEAR 30N84W TO
27N86W TO 26N91W. ALSO...A SURFACE TROUGH EXTENDS FROM 27N86W TO
THE NW YUCATAN PENINSULA NEAR 21N89W. WHILE REMAINING A
RELATIVELY DRY FRONT...LOW LEVEL CONVERGENCE AND INSTABILITY E
OF THE BOUNDARY IS RESULTING IN SCATTERED SHOWERS AND ISOLATED
TSTMS FROM ACROSS THE SE GULF AND STRAITS OF FLORIDA FROM
23N-26N E OF 84W. ALL OF THIS ACTIVITY IS FURTHER SUPPORTED BY
UPPER LEVEL DIFFLUENCE IN MOIST ZONAL WLY UPPER LEVEL FLOW.
ACROSS THE N GULF AND N OF THE COLD FRONT...GENERALLY FAIR
WEATHER IS OCCURRING WHERE STABLE ATMOSPHERIC CONDITIONS AND A
SURFACE RIDGE ARE PRESENT. A FEW EWD MOVING SCATTERED TO BROKEN
HIGH LEVEL CONVECTIVE DEBRIS CLOUDS ARE ACROSS THE WRN GULF FROM
REMAINING CONVECTION ACROSS INLAND ERN MEXICO THIS EVENING.

CARIBBEAN SEA...
DEEP LAYER DRY AIR AND SUBSIDENCE IN NWLY FLOW ALOFT...ALONG
WITH MID-LEVEL DRY SAHARAN AIR...ARE RESULTING IN GENERALLY FAIR
WEATHER ACROSS MUCH OF THE CARIBBEAN. FRESH TO STRONG TRADE
WINDS ARE OCCURRING ACROSS THE CARIBBEAN AS AN EARLIER QSCAT
PASS AROUND 2300 UTC OBSERVED MAINLY 15 TO 20 KT ACROSS THE
CENTRAL AND WRN CARIBBEAN. THE STRONGEST OF THESE WINDS...UP TO
25 KT...WERE OBSERVED NEAR THE NRN COASTS OF COLOMBIA AND NWRN
VENEZUELA. ALSO...ATMOSPHERIC INSTABILITY ASSOCIATED WITH AN
UPPER LEVEL TROUGH OVER THE NE CARIBBEAN IS SUPPORTING ISOLATED
SHOWERS OVER THE US/UK VIRGIN ISLANDS...PUERTO RICO AND PORTIONS
OF THE LEEWARD ISLANDS.

ATLANTIC OCEAN...
UPPER LEVEL DIFFLUENCE AND DEEP LAYER MOISTURE ASSOCIATED WITH
AN UPPER LEVEL RIDGE OVER THE SW NORTH ATLC AND A UPPER LEVEL
LONGWAVE TROUGH OVER THE ERN CONUS ARE SUPPORTING SCATTERED
SHOWERS AND TSTMS FROM 23N-29N W OF 72W INCLUDING THE NW AND
CENTRAL BAHAMAS AND THE STRAITS OF FLORIDA. ANOTHER AREA OF
SCATTERED SHOWERS AND TSTMS IS LOCATED OFF THE GEORGIA AND SOUTH
CAROLINA COAST N OF 30N W OF 78W DUE TO A COLD FRONT DRAPED
60/90 NM INLAND ALONG THE ERN CONUS COAST. ALSO...UPPER LEVEL
DIVERGENCE AND DEEP LAYER MOISTURE TO THE NW OF AN UPPER LEVEL
HIGH CENTERED NEAR 25N55W ARE SUPPORTING SCATTERED SHOWERS FROM
25N-32N BETWEEN 61W-66W. THIS ACTIVITY IS BEING ENHANCED BY LOW
LEVEL CONVERGENCE NEAR A SURFACE TROUGH EXTENDING FROM 30N64W TO
27N66W. A SURFACE TROUGH IS ANALYZED NE OF THE LEEWARD ISLANDS
AND EXTENDS FROM 24N57W TO 20N59W. SCATTERED SHOWERS ARE
OBSERVED FROM 20N-27N BETWEEN 51W-59W. FARTHER TO THE E...AN
UPPER LEVEL TROUGH AXIS ALONG 27N25W 22N37W 21N47W IS ASSOCIATED
WITH A COLD FRONT EXTENDING INTO THE DISCUSSION AREA NEAR 32N27W
ALONG 29N30W TO 27N36W CONTINUING WWD AS A STATIONARY FRONT TO
28N45W. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS
WITHIN 60 NM EITHER SIDE OF THE FRONTS ACROSS THE CENTRAL ATLC.
BEHIND THE FRONTS...A 1025 MB SURFACE HIGH IS CENTERED NEAR
32N53W. SUBSIDENCE ASSOCIATED WITH THIS SURFACE HIGH IS
RESULTING IN GENERALLY FAIR WEATHER BEHIND THE FRONTAL BOUNDARY.
ACROSS THE E ATLC...A SURFACE RIDGE IS PRESENT WHERE MAINLY
ZONAL FLOW ALOFT IS OCCURRING AND FAIR WEATHER CONDITIONS
PERSIST. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL RIDGE IS
PRESENT S OF 15N E OF 55W WITH AN UPPER LEVEL HIGH NEAR 7N33W.
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE UPPER LEVEL HIGH AND
RIDGE IS ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ AND
THE TROPICAL WAVE ALONG 49W S OF 9N.

$$
HUFFMAN


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