[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 291109
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU MAY 29 2014

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS OVER THE EASTERN TROPICAL ATLC WITH AXIS ALONG
32W S OF 9N MOVING W AT 15-20 KT. THE WAVE IS ON THE WESTERN
PERIPHERY OF A SAHARAN DUST OUTBREAK NOTED ON METEOSAT PSEUDO
NATURAL COLOR IMAGERY. THE SOUTHERN PORTION OF THE WAVE IS
EMBEDDED WITHIN THE ITCZ AXIS. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS WITHIN 120 NM E AND 60 NM W OF THE WAVE
FROM 04N-05N.

A TROPICAL WAVE IS ALONG 45W S OF 08N MOVING NEAR 15 KT. DURING
THE LAST 24 HOURS. AN INVERTED-V CLOUD PATTERN IS NOTED ON IR
SHORTWAVE IMAGERY ANIMATION. SCATTERED MODERATE/ISOLATED
CONVECTION IS WITHIN 120 NM E OF THE WAVE FROM 04N TO 05N.
SIMILAR ACTIVITY IS RACING OUT AHEAD OF THE WAVE WITHIN 30 NM OF
LINE FROM 05N46W TO 04N51W. THE 24 HOUR FORECAST WILL BRING THE
WAVE TO INLAND EASTERN VENEZUELA AND GUYANA...ATTENDANT BY
ABUNDANT MOISTURE ALONG WITH SCATTERED TO NUMEROUS SHOWERS AND
TSTMS WITH GUSTY WINDS.

A TROPICAL WAVE IS MOVING ACROSS THE SOUTHERN CARIBBEAN BASIN
WITH AXIS ALONG 70W S OF 14N MOVING W NEAR 20 KT. DURING THE
LAST 24 HOURS. STRONG UPPER LEVEL SW WINDS OVER THE EASTERN
CARIBBEAN CONTINUE TO LIMIT THE CONVECTION ASSOCIATED WITH THE
WAVE TO SCATTERED SHOWERS AND ISOLATED WEAK TSTMS E OF THE WAVE
TO 64W. AS THE WAVE CONTINUES WESTWARD OVER THE NEXT 24
HOURS...IT WILL COME UNDER A SUBSTANTIAL AMOUNT SUBSIDENCE/DRY
AIR ALOFT THAT WILL KEEP ANY SHOWER/TSTM ACTIVITY THAT OCCURS
TO A MINIMUM.

A TROPICAL WAVE IS OVER THE SW CARIBBEAN ALONG 81W S OF 15N
MOVING W NEAR 15 KT. IT IS PRESENTLY ENHANCING SCATTERED
MODERATE/ISOLATED STRONG CONVECTION S OF 10N W OF 80W. THIS WAVE
IS FORECAST TO MOVE ACROSS CENTRAL AMERICA S OF THE
HONDURAS/NICARAGUA BORDER OVER THE NEXT 24 HOURS...WITH
ASSOCIATED TSTM ACTIVITY EXPECTED TO BE CONFINED TO MAINLY FROM
SOUTHERN NICARAGUA ON SOUTHWARD AS DRY AIR ALOFT WILL KEEP THE
ACTIVITY TO AT MOST ISOLATED IN CONVERGE N OF SOUTHERN NICARAGUA.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM A 1008 MB LOW ALONG THE
AFRICAN COAST NEAR 13N16W SW TO 0522W WHERE THE ITCZ AXIS
CONTINUES TO 04N30W. THE ITCZ RESUMES W OF A TROPICAL WAVE FROM
04N33W TO 03N38W TO 03N45W...THEN AGAIN W OF A SECOND TROPICAL
WAVE FROM 03N46W TO THE COAST OF S AMERICA NEAR 0N51W. BESIDES
THE CONVECTION MENTIONED WITH THE TROPICAL WAVES...SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS NOTED WITHIN 120 NM S OF
THE ITCZ BETWEEN 24W-28W...AND ALSO S OF 02N W OF 46W. ISOLATED
MODERATE CONVECTION EXISTS ELSEWHERE FROM 01N TO 07N W OF 29W.
SCATTERED MODERATE CONVECTION IS WELL S OF THE MONSOON TROUGH
FROM 02N TO 06N E OF 17W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVELS...THE EASTERN PERIPHERY OF A BROAD AREA OF
MID/UPPER RIDGING COVERS THE MUCH OF THE GULF. A JET STREAM IS
EVIDENT ACROSS THE EASTERN PERIPHERY OF THE RIDGING EXTENDING
FROM NE TEXAS AT 28N97W SE TO THE NE YUCATAN CHANNEL. NW WINDS
OF 60-90 KT SW OF THIS JET STREAM BRANCH ARE ADVECTING DEBRIS
MOISTURE...IN THE FORM OF BROKEN CIRRUS CLOUDS...FROM EARLIER
DEEP CONVECTION THAT WAS OVER EASTERN MEXICO SEWD TO THE S
CENTRAL GULF AND YUCATAN CHANNEL AREA. A PERSISTENT DEEP LAYER
LOW IS OVER SOUTHERN ARKANSAS WITH SPOKES OF VORTICITY ROTATING
AROUND IT. ITS CORRESPONDING SURFACE LOW OF 1009 MB IS OVER NE
LOUISIANA NEAR 33N92W WITH A TROUGH EXTENDING FROM IT SW TO LAKE
CHARLES...AND TO 27N96W. LATEST NWS DOPPLER RADAR IMAGERY ALONG
WITH SATELLITE ANIMATION SHOW SCATTERED MODERATE/ISOLATED STRONG
CONVECTION REMAINING QUITE ACTIVE OUT AHEAD OF THE TROUGH N OF
27N BETWEEN 87W AND 91W. ELSEWHERE AT THE SURFACE...WEAK
ATLANTIC RIDGING STRETCHES WESTWARD ROUGHLY ALONG 31N AND W TO
NEAR 88W. THE PRES GRADIENT S OF THE RIDGE IS ALLOWING FOR
GENERALLY SE TO S 10-15 KT WINDS OVER THE EASTERN GULF...WHILE A
LITTLE STRONGER GRADIENT BETWEEN THE RIDGE AND THE SURFACE
TROUGH IS ALLOWING FOR S 15-20 KT WINDS OVER THE NORTHERN
PORTION OF THE CENTRAL GULF. LIGHT NORTHERLY WINDS ARE W OF THE
TROUGH. THE DEEP LAYER LOW WILL REMAIN NEARLY STATIONARY THROUGH
MOST OF TODAY BEFORE IT BEGINS TO RETROGRADE BACK TO THE WSW
LATER TODAY AND TONIGHT...AND THEN TO THE VICINITY OF EASTERN
TEXAS ON FRI AS THE WEAK RIDGE WEAKENS FURTHER. THIS WILL ALLOW
FOR THE ATMOSPHERE OVER MUCH OF THE EASTERN AND CENTRAL GULF
WILL DESTABILIZE ALLOWING FOR SHOWERS AND TSTMS TO DEVELOP. SOME
OF THIS ACTIVITY WILL BE ACCOMPANIED BY GUSTY WINDS.

CARIBBEAN SEA...
TWO LOW AMPLITUDE TROPICAL WAVES ARE OVER THE SOUTHERN CARIBBEAN
SEA AS DESCRIBED ABOVE UNDER TROPICAL WAVE. IN THE UPPER
LEVELS....THE SE PERIPHERY OF THE RIDGE MENTIONED ABOVE UNDER
GULF OF MEXICO COVERS THE WESTERN CARIBBEAN SEA W OF ABOUT 80W.
STRONG NW FLOW OVER THE TOP OF THIS RIDGE IS SENDING HIGH LEVEL
MOISTURE...IN THE FORM OF SCATTERED TO BROKEN CIRRUS CLOUDS...
SEWD TO THE FAR NW CARIBBEAN. A PERSISTENT UPPER LEVEL TROUGH IS
OVER THE REMAINDER OF THE CARIBBEAN WITH AXIS ROUGHLY ALONG 75W.
SW FLOW ALOFT E OF THE TROUGH CONTINUES TO ADVECT MAINLY
OVERCAST MID/HIGH LEVEL CLOUDS NEWD ACROSS THE EASTERN CARIBBEAN
TO THE SE OF A LINE FROM THE VIRGIN ISLANDS SW TO THE COAST OF
COLOMBIA AT 12N73W. THE SCATTERED SHOWERS AND ISOLATED TSTMS
THAT EARLIER WERE UNDERNEATH THESE CLOUDS HAVE RECENTLY
DIMINISHED TO MOSTLY ISOLATED. THE REMAINDER OF THE SEA REMAINS
UNDER GENERALLY FAIR CONDITIONS WITH JUST WESTWARD MOVING LOW
CLOUDS IN THE TRADE WIND FLOW WITH POSSIBLE ISOLATED SHOWERS.
THE UPPER TROUGH IS FORECAST TO CONTINUE TO MOVE E THROUGH THE
NEXT 24 HOURS WHILE WEAKENING AS HIGH BECOMES MORE OF THE
DOMINANT SYNOPTIC FEATURE OVER THE SEA.

...HISPANIOLA...
WESTWARD MOVING LOW LEVEL MOISTURE IN PATCHES ALONG THE BASE OF
AN UPPER TROUGH OVER THE ISLAND WILL ALLOW FOR ISOLATED SHOWERS
OR TSTMS OVER MOST OF THE ISLAND THROUGH THE NEXT 24 HOURS.
ISOLATED TSTMS MAY FORM AGAIN OVER THE WATERS JUST W OF HAITI
LATER TODAY AND INTO TONIGHT. STRONG UPPER LEVEL WESTERLY WINDS
ACROSS THE BASE OF THE TROUGH WILL TEND TO SHEAR OFF THE TOPS OF
THE SHOWER AND TSTM ACTIVITY NOT ALLOWING FOR THEN TO ATTAIN A
LONG DURATION OF OCCURRENCE THROUGH FRI NIGHT.

ATLANTIC OCEAN...
UPPER LEVEL HIGH PRES IS OVER THE CENTRAL ATLANTIC BETWEEN 35W
AND 58W WITH THE ASSOCIATED ANTICYCLONE CENTER NEAR 10N53W. TO
ITS E...AN UPPER LEVEL TROUGH IS OVER THE EASTERN ATLANTIC N OF
09N. AN UPPER LEVEL LOW IS OVER THE WESTERN ATLANTIC NEAR 27N61W
MOVING QUICKLY EASTWARD. A TROUGH EXTENDS FROM THE LOW SW TO
HISPANIOLA. A JET STREAM BRANCH WITH A 60-90 KT WIND MAX
EXTENDS FROM THE VIRGIN ISLANDS NEWD TO 24N57W...AND TO 27N45W.
WATER VAPOR IMAGERY SHOWS A 360 NM WIDE BAND OF BROKEN TO
OVERCAST MID/HIGH LEVEL CLOUDS STREAMING NE TO E TO THE S OF THE
JET. AT THE SURFACE...A 1028 MB HIGH CENTER IS LOCATED OVER THE
EASTERN ATLANTIC NEAR 34N29W WITH A RIDGE EXTENDING SW TO 32N41W
TO 27N56W. THE COMBINATION OF THE RIDGE AND UPPER LEVEL HIGH
PRES OVER THE AREA IS KEEPING THE EASTERN ATLANTIC PORTION UNDER
VERY STABLE ATMOSPHERIC CONDITIONS. A SHORTWAVE TROUGH OVER THE
FAR WESTERN PORTION OF THE AREA ALONG 78W IS TRIGGERING OFF A
SMALL POCKET OF SCATTERED MODERATE CONVECTION FROM 22N TO 25N
BETWEEN 77W AND 79W. THIS ACTIVITY WILL SHIFT EASTWARD OVER THE
CENTRAL BAHAMAS AND MOST OF THE SE BAHAMAS THROUGH FRI. E TO SE
WINDS OF 10-15 KT ARE NOTED ACROSS THE BASIN N OF 18N W OF
45W...WHILE NE TO E WINDS OF 15-20 KT ARE ELSEWHERE.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
AGUIRRE


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