[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 051047
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN JUN 05 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...

TROPICAL WAVE OFF THE COAST OF AFRICA ALONG 18W S OF 15N MOVING
W AT AN ESTIMATED SPEED OF 15 KT OR ABOUT 5-6 DEG/DAY.  THE WAVE
HAS A WELL-DEFINED SATELLITE SIGNATURE BUT CONVECTION IS WEAK.
WIDELY SCATTERED WEAK TO MODERATE CONVECTION FROM 7N-12N E OF
20W TO THE COAST OF AFRICA.

CENTRAL ATLC TROPICAL WAVE IS ALONG 45W S OF 15N MOVING W NEAR
15 KT OR ABOUT 5-6 DEG/DAY.  THERE IS CURRENTLY NO SIGNIFICANT
CONVECTION OR CLOUD SIGNATURE TO TRACK THIS WAVE AND THE CURRENT
POSITION IS BASED UPON EXTRAPOLATION FROM AN EARLIER QUIKSCAT
PASS.

TROPICAL WAVE OVER THE E CARIBBEAN ALONG 67W/68W S OF 17N MOVING
W 15-20 KT OR 7-8 DEG/DAY.  THE WAVE CONTINUES TO INTERACT WITH
A WELL-DEFINED MID/UPPER LOW OVER THE CENTRAL CARIBBEAN S OF
HISPANIOLA.  AS A RESULT...THE SATELLITE SIGNATURE IS MASKED BUT
ANALYSIS OF UPPER AIR TIMESECTIONS AND UW-CIMSS SATELLITE
DERIVED PRODUCTS SUPPORT THE CURRENT POSITION IN ADVANCE OR W OF
THE DEEPEST CONVECTION.  AS SUCH...THE WAVE APPEARS TO BE OUT
RUNNING THE UPPER LOW AND THUS MOVING INTO A LESS FAVORABLE
UPPER LEVEL ENVIRONMENT. ASSOCIATED CONVECTION IS BECOMING
INCREASINGLY DISPLACED E OF THE AXIS WITH SCATTERED
MODERATE/ISOLATED STRONG ACTIVITY FROM 11N-17N BETWEEN 55W-66W
INCLUDING THE WINDWARD ISLANDS AND PORTIONS OF THE LEEWARD
ISLANDS.   THIS ACTIVITY WILL CONTINUE TO PRODUCE SQUALLY
WEATHER WITH LOCALLY HEAVY RAINFALL AND GUSTY WINDS OVER THE
CARIBBEAN TODAY.  CONVECTION HAS BEEN SPREADING MORE NWD DURING
THE LAST FEW HOURS AND THIS TREND IS EXPECTED TO CONTINUE WITH
INCREASING CLOUDINESS AND SHOWERS/TSTMS OVER THE NE
CARIBBEAN...INCLUDING PUERTO RICO AND THE VIRGIN
ISLANDS...TODAY.  IN FACT...GUIDANCE IS INDICATING A POTENTIALLY
VERY WET PATTERN UNFOLDING LATE SUNDAY INTO MON OVER THE NE
CARIBBEAN.

W CARIBBEAN TROPICAL WAVE IS ALONG 83W S OF 15N MOVING W 15 KT.
THE WAVE IS EMBEDDED WITHIN BROAD LOW LEVEL CYCLONIC GYRE OVER
CENTRAL AMERICA AND THE E PACIFIC...SO IT HAS AN ILL-DEFINED
SIGNATURE IN SATELLITE IMAGERY. THE SRN PART OF THE WAVE IS
FOSTERING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION OVER
THE SW CARIBBEAN MOVING INTO NICARAGUA.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 14N10W 6N30W 12N65W. ISOLATED
MODERATE CONVECTION ALONG THE ENTIRE ITCZ AXIS.

...DISCUSSION...

GULF OF MEXICO...
AFTER PERSISTING OVER THE E GLFMEX FOR SEVERAL DAYS...THE SHARP
MIDDLE TO UPPER LEVEL TROUGH HAS FINALLY WEAKENING.  LATEST
WATER VAPOR IMAGERY SHOWS THAT THE UPPER LEVEL PATTERN HAS
FLATTENED DURING THE LAST 24 HOURS WITH THE FLOW NOW SW RATHER
THAN S.  THUS...THE MAIN PLUME OF TROPICAL MOISTURE ADVECTION
FROM THE CARIBBEAN HAS BEEN SHUNTED EWD WITH SUBSIDENCE AND DRY
AIR ALOFT NOW OBSERVED FILTERING EWD OVER FLORIDA.  THIS UPPER
LEVEL DRYING SHOULD RESULT IN A DECREASE IN CLOUD COVER AND
SHOWER/TSTM AREAL COVERAGE OVER FLORIDA TODAY.  HOWEVER...WITH
LOW LEVEL MOISTURE STILL HIGH AND SUNSHINE FINALLY
RETURNING...DAYTIME HEATING WILL LIKELY GET THE SEABREEZES AND
TYPICAL AFTERNOON CONVECTION GOING AGAIN. OVER THE W
GLFMEX...VERY DRY/STABLE CONDITIONS ALOFT ARE EXPECTED TO
CONTINUE SUPPRESSING CLOUDINESS AND SHOWER ACTIVITY TODAY SAVE
SOME HIGH LEVEL DEBRIS CLOUDS MOVING OFF THE SE COAST OF TEXAS
FROM EARLIER INLAND CONVECTION.

CARIBBEAN...
THE PRIMARY WEATHER MAKER OF THE CARIBBEAN TONIGHT IS A
RETROGRADING UPPER LEVEL LOW JUST S OF HISPANIOLA.  THE UPPER
LOW IS PRODUCING CONFLUENCE AND DRY/STABLE CONDITIONS TO THE
WEST BETWEEN 70W-80W WITH DIFFLUENCE TO THE EAST PRODUCING AN
OPTIMAL ENVIRONMENT FOR THE DEVELOPMENT OF SHOWERS/TSTMS OVER
THE E CARIBBEAN.  THE UPPER LOW IS EXPECTED TO MOVE SLOWLY NW
PRODUCING INCREASING CLOUDINESS AND SHOWERS/TSTMS OVER THE NE
CARIBBEAN DURING THE NEXT 24-36 HOURS.  IN FACT...NUMERICAL
GUIDANCE IS INDICATING A FAIRLY WET/STORY PATTERN UNFOLDING N OF
15N E OF 70W LATE SUN INTO MONDAY AS THE UPPER LOW AND MOISTURE
FROM THE TROPICAL WAVE CONTINUE TO INTERACT...SEE TROPICAL WAVE
DISCUSSION ABOVE FOR MORE DETAILS.  OVER THE W CARIBBEAN...WEAK
UPPER LEVEL TROUGHING OVER THE BAY OF CAMPECHE AND S MEXICO
CONTINUES TO PRODUCE WIDELY SCATTERED MODERATE CONVECTION WITHIN
100 NM EITHER SIDE OF A LINE FROM CENTRAL HONDURAS TO W CUBA.
OVER CENTRAL AMERICA...COPIOUS DEEP-LAYERED TROPICAL MOISTURE
REMAINS IN PLACE SUPPORTING CLOUDINESS AND AREAS OF STRONG
CONVECTION ESPECIALLY NEAR A TROPICAL WAVE ALONG 83W.

ATLANTIC...
STRONG MIDDLE TO UPPER LEVEL RIDGING REMAINS OVER THE W ATLC
WATERS WITH AMPLE TROPICAL MOISTURE OVER THE W PERIPHERY SURGING
NEWD ACROSS CUBA AND THE BAHAMAS. THIS IS CREATING WIDESPREAD
CLOUDINESS AND WIDELY SHOWERS/TSTMS FROM W CUBA OVER THE FLORIDA
STRAITS AND THE N BAHAMAS.  SHIFTING EWD...A STRONG LONGWAVE
TROF IS DIGGING OVER THE CNTRL ATLC ROUGHLY ALONG 37W WITH
ATTENDANT WEAKENING STATIONARY FRONT ENTERING THE AREA ALONG
32N35W 25N40W TO A 1016 MB LOW NEAR 23N52W...THEN NW TO 25N63W.
BROKEN TO OVERCAST CLOUDINESS AND WIDELY SCATTERED SHOWERS
EXTEND UP TO 100 NM EITHER SIDE OF FRONT ESPECIALLY E OF 55W.
OVER THE E ATLC...A HIGH OVER LOW BLOCKING PATTERN REMAINS WITH
THE UPPER LOW CENTERED JUST N OF THE CANARY ISLANDS. THIS
FEATURE IS NOT PRODUCING ANY SIGNIFICANT WEATHER OWING TO THE
LARGE AREA OF SUBSIDENCE AND DRY AIR N OF 20N E OF 35W. OVER THE
TROPICAL ATLC....A WEAKNESS IS DEVELOPING IN THE E/W ORIENTED
RIDGE ALONG 10N COURTESY OF AN AMPLIFYING TROUGH OVER THE
CENTRAL ATLC.

$$
RHOME



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