[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270000
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI JUN 26 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...

AN ACTIVE TROPICAL WAVE IN THE WRN CARIBBEAN IS FROM 10N-21N
ALONG 84W MOVING W NEAR 15 KT. ACCOMPANYING THE TROPICAL WAVE IS
A 1009 MB SURFACE LOW ANALYZED ALONG THE WAVE AXIS NEAR 17.5N. A
LARGE CLUSTER OF SCATTERED TO NUMEROUS STRONG CONVECTION IS
FOUND E OF THE SURFACE LOW FROM 14N-19N BETWEEN 81W-85W AND IS
IN BETWEEN TWO UPPER LEVEL FEATURES. STRONG MOIST SLY MIDDLE TO
UPPER LEVEL FLOW BETWEEN AN UPPER LOW OVER THE YUCATAN PENINSULA
AND ERN BAY OF CAMPECHE AND AN UPPER LEVEL HIGH CENTERED OVER
JAMAICA IS CONTINUING TO ENHANCE THE CONVECTION ASSOCIATED WITH
THE TROPICAL WAVE AND SURFACE LOW. GLOBAL MODELS INDICATE THIS
AREA OF DISORGANIZED WEATHER WILL MOVE TOWARDS THE SRN GULF OF
MEXICO LATE SATURDAY INTO SUNDAY...WITH THE POSSIBILITY OF
BECOMING A TROPICAL CYCLONE IN THE NEXT 48 HOURS. IN THE
MEANTIME...LOCALLY HEAVY RAINFALL WILL CONTINUE TO FALL IN THE
VICINITY OF THIS SYSTEM OVER HONDURAS AND IN THE NW CARIBBEAN...
SPREADING NWD OVER PORTIONS OF THE YUCATAN PENINSULA AND MUCH OF
WRN AND CENTRAL CUBA.

...TROPICAL WAVES...

A TROPICAL WAVE IN THE CENTRAL ATLC EXTENDS FROM 14N36W TO 5N38W
MOVING W NEAR 10 KT. THIS WAVE IS ASSOCIATED WITH WEAK LOW LEVEL
CYCLONIC CIRCULATION AND MAINLY CONFLUENT SURFACE FLOW ALONG THE
ITCZ AXIS NEAR 6N. THE WAVE IS VOID OF ANY DEEP CONVECTION WITH
ONLY CLUSTERS OF SCATTERED SHOWERS FROM 2N-11N E OF THE WAVE
AXIS TO 10W.

A TROPICAL WAVE IN THE ERN CARIBBEAN EXTENDS FROM 20N67W ACROSS
WRN PUERTO RICO TO CURACAO AND INLAND ACROSS WRN VENEZUELA TO
NEAR 8N69W MOVING W NEAR 12 KT. THIS WAVE IS ASSOCIATED WITH A
MOISTURE MAXIMUM BASED ON TOTAL PRECIPITABLE WATER IMAGERY.
WHILE NO DEEP CONVECTION IS OBSERVED ON SATELLITE IMAGERY...
ISOLATED SHOWERS ARE DEPICTED SURROUNDING THE SAN JUAN DOPPLER
RADAR ACROSS THE MONA PASSAGE AND INTO THE N/CENTRAL CARIBBEAN N
OF 15N BETWEEN 65W-70W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 12N16W 7N35W 6N39W AND INTO NRN
SOUTH AMERICA NEAR 4N51W. CLUSTERS OF SCATTERED MODERATE
CONVECTION ARE FROM 5N-12N BETWEEN 12W-19W. ELSEWHERE...
SCATTERED SHOWERS WITH ISOLATED EMBEDDED MODERATE CONVECTION IS
WITHIN 200 NM ON EITHER SIDE OF THE AXIS BETWEEN 20W-35W.

...DISCUSSION...

GULF OF MEXICO...
A 1010 MB SURFACE LOW OVER SE LOUISIANA NEAR 31N91W AND A
SURFACE TROUGH ANALYZED OVER THE N/CENTRAL GULF ALONG 29N87W
27N89W 27N93W ARE SUPPORTING SCATTERED SHOWERS ALONG THE
LOUISIANA GULF COAST AND N/CENTRAL GULF N OF 26N BETWEEN
85W-93W. A STRONG UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED
OVER N TEXAS IS PROVIDING MAINLY NE FLOW ALOFT AND PROVIDING AN
OVERALL DRY AND RELATIVELY STABLE ATMOSPHERE OVER THE GULF NW OF
A LINE FROM THE BIG BEND REGION OF FLORIDA TO THE WRN BAY OF
CAMPECHE. ACROSS THE FLORIDA PENINSULA AND SE GULF...INCLUDING
NRN PORTIONS OF THE YUCATAN PENINSULA...UPPER LEVEL TROUGHING
EXTENDS FROM THE W ATLC ACROSS THE SE GULF TO AN UPPER LOW NEAR
20N92W. MOIST AND UNSTABLE SLY MIDDLE TO UPPER LEVEL FLOW E OF
THE TROUGH AXIS IS GENERATING SCATTERED SHOWERS AND TSTMS SE OF
A LINE FROM JACKSONVILLE FLORIDA TO 25N86W AND TO THE NW TIP OF
THE YUCATAN PENINSULA NEAR 21N90W. WITH THE TROPICAL WAVE ALONG
84W IN THE WRN CARIBBEAN...POSSIBLE DEVELOPMENT OF THIS SYSTEM
IS FORECAST AS THE WAVE AND SURFACE LOW TRACK INTO THE SRN GULF
BY LATE SATURDAY INTO SUNDAY.

CARIBBEAN SEA...
TWO TROPICAL WAVES ARE MOVING ACROSS THE CARIBBEAN SEA WITH THE
UPPER LEVEL PATTERN ABOVE OF EACH WAVE PROVIDING A VERY
DIFFERENT OUTCOME IN THE WEATHER EXPERIENCED AT THE SURFACE.
ACROSS THE ERN CARIBBEAN...NLY UPPER LEVEL FLOW DOMINATES
PROVIDING A VERY DRY AND STABLE ATMOSPHERE E OF 70W. HOWEVER...
WITH THE LOW-LEVEL TROPICAL WAVE ALONG APPROXIMATELY 68W...
ISOLATED SHOWERS ARE OBSERVED N OF 15N BETWEEN 65W-70W...
INCLUDING THE MONA PASSAGE. E OF THE WAVE AXIS ON SATELLITE
IMAGERY...A SAHARAN AIR LAYER IS NOTED MOVING ACROSS THE LESSER
ANTILLES TO NEAR 66W. ACROSS THE WRN CARIBBEAN W OF 70W...AN
UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER JAMAICA IS
PROVIDING AN UPPER LEVEL DIFFLUENT PATTERN NEAR THE TROPICAL
WAVE AND SURFACE LOW NEAR 17.5N84W. THIS PATTERN IS CONTINUING
TO ENHANCE THE SCATTERED TO NUMEROUS STRONG CONVECTION FROM
14N-19N BETWEEN 81W-85W.

ATLANTIC OCEAN...
UPPER LEVEL TROUGHING EXTENDS ALONG THE ERN SEABOARD OF THE
CONUS AND DIPS INTO THE SW NORTH ATLC TO 25N. THIS UPPER LEVEL
TROUGH SUPPORTS A SURFACE TROUGH EXTENDING FROM 26N71W TO 32N62W
AND CONTINUES N OF THE DISCUSSION AREA. AN AREA OF UPPER LEVEL
DIFFLUENCE LOCATED E OF THE UPPER TROUGHING IS GENERATING
SCATTERED SHOWERS FROM 24N-32N BETWEEN 59W-69W. THE MIDDLE TO
UPPER LEVEL PLUME OF MOISTURE EXTENDS FARTHER SW ACROSS THE
BAHAMAS...SRN FLORIDA AND CUBA GENERATING SCATTERED SHOWERS AND
TSTMS FROM 20N-29N BETWEEN 74W-81W. FARTHER TO THE E...A 1023 MB
SURFACE HIGH CENTERED NEAR 33N49W IS BRINGING GENERALLY FAIR
WEATHER TO MUCH OF THE CENTRAL ATLC. AN UPPER LEVEL TROUGH IS
SWEEPING ACROSS THE FAR PORTIONS OF THE NE ATLC WITH THE UPPER
TROUGHING EXTENDING W-SW ALONG 26N40W TO AN UPPER LEVEL LOW
CENTERED NEAR 21N53W. THE UPPER LEVEL TROUGH SUPPORTS A COLD
FRONT THAT CLIPS THE DISCUSSION AREA ALONG 32N28W 30N32W TO
32N37W. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM 31N28W TO
27N40W. ENHANCED CLOUDINESS AND POSSIBLE SCATTERED SHOWERS
SURROUND THE SURFACE FRONT AND TROUGH N OF 26N BETWEEN 20W-40W.
A BROAD UPPER RIDGE CENTERED NEAR 15N35W DOMINATES THE TROPICAL
ATLC S OF 22N.

$$
HUFFMAN


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