[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251051
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE JUN 25 2013

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
1022 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS CROSSING THE DOMINICAN REPUBLIC WITH AXIS
EXTENDING FROM 21N67W TO 14N72W. THIS WAVE IS MOVING W-NW AT 10-
15 KT IN THE SW PERIPHERY OF A BROAD SURFACE RIDGE COVERING THE
ATLC...PORTIONS OF THE CARIBBEAN AND THE GULF. THE PORTION OF
THE WAVE N-NE OF LA HISPANIOLA IS EMBEDDED IN A MODERATE HUMID
ENVIRONMENT AT THE LOWER LEVELS. SOME OF THIS HUMIDITY HAS MOVED
INLAND E OF THE AXIS AS WELL AS SE OF THE AXIS N OF 16N. A LOW
HUMIDITY ENVIRONMENT AT THE LOWER LEVELS IS OBSERVED ACROSS LA
HISPANIOLA WEST OF THE WAVE AXIS AND AHEAD OF THE WAVE IN THE
CENTRAL CARIBBEAN. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
ARE HAPPENING NE OF THE DOMINICAN REPUBLIC ASSOCIATED WITH THE
WAVE AND BEING ENHANCED BY UPPER LEVEL DIFFLUENCE FROM A
CYCLONIC CIRCULATION IN THE W ATLC AND A NARROW RIDGE THAT HAS
FORMED NE OF PUERTO RICO.

TROPICAL WAVE CROSSING THE SOUTHERN LESSER ANTILLES WITH AXIS
EXTENDING FROM 20N59W TO 11N61W. THE WAVE AXIS IS MOVING W-NW AT
15 KT. THE ENVIRONMENT IN WHICH THE WAVE IS EMBEDDED IS
CHARACTERIZED BY MODERATE MOISTURE IN THE LOWER LEVELS N OF 16N
AND A LOW HUMID ENVIRONMENT S OF 16N EXTENDING ACROSS THE
EASTERN CARIBBEAN. WATER VAPOR IMAGERY DEPICT THIS DRY REGION
AHEAD OF THE WAVE ALSO IN THE MIDDLE LEVELS. SCATTERED SHOWERS
ARE OCCURRING WITHIN 180 NM EAST OF THE WAVE AXIS COINCIDING WITH
THE REGION OF MODERATE MOISTURE OBSERVED IN THE TOTAL
PRECIPITABLE WATER IMAGERY.

A NEW TROPICAL WAVE HAS BEEN DETECTED EMBEDDED WITHIN THE ITCZ
WITH AXIS ALONG 10N34W TO 02N36W. IT IS A LOW AMPLITUDE WAVE IN
THE 700 MB AND 315K POTENTIAL VORTICITY AND WIND GUIDANCE
PREDICTS THIS WAVE TO MOVE W-NW ENTERING THE EASTERN CARIBBEAN
IN FOUR DAYS. CURRENTLY SCATTERED MODERATE TO STRONG CONVECTION
IS FROM 04N-06N BETWEEN 34W-40W COINCIDING WITH HIGH MOISTURE AT
THE LOWER LEVELS WITHIN THE ITCZ AXIS. NO CONVECTION IS OCCURRING
IN THE NORTHERN ENVIRONMENT OF THE WAVE DUE TO THE PRESENCE OF
SAHARAN DRY AIR.

...THE ITCZ/THE MONSOON TROUGH...
THE MONSOON TROUGH PASSES THROUGH COASTAL WEST AFRICA NEAR
11N15W TO 09N22W 08N25W. THE ITCZ STARTS NEAR 08N25W AND IT
CONTINUES TO 06N35W. THE ITCZ AXIS RESUMES WEST OF A TROPICAL
WAVE FROM 05N36W TO 06N45W. BESIDES THE CONVECTION ALREADY
DESCRIBED ABOVE WITHIN THE TROPICAL WAVE ENVIRONMENT EMBEDDED IN
THE ITCZ...SCATTERED MODERATE CONVECTION IS FROM 05N-08N BETWEEN
25W-28W.

...DISCUSSION...

THE GULF OF MEXICO...
BROAD SURFACE RIDGING FROM A SET OF HIGH PRESSURES N OF THE AREA
OVER THE NORTH ATLC EXTENDS INTO THE GULF GENERATING RETURN FLOW
IN THE RANGE OF 10-15 KT ACROSS THE BASIN. MODERATE MOISTURE AT
THE LOWER AND MIDDLE LEVELS COMBINED WITH UPPER LEVEL DIVERGENCE
FROM AN ANTICYCLONIC CIRCULATION EAST OF 88W MAY ENHANCE
ISOLATED SHOWERS IN THIS PART OF THE BASIN THIS MORNING. BOTH
PRECIPITABLE WATER AND WATER VAPOR IMAGERY SHOW A DRY
ENVIRONMENT IN THE LOWER AND MIDDLE LEVELS W OF 88W WHICH IS
SUPPRESSING ANY TYPE OF CONVECTIVE ACTIVITY. NO SIGNIFICANT
CHANGES ARE EXPECTED DURING THE NEXT 24 HOURS AS THE CURRENT
WEATHER PATTERNS IN THE LOWER AND UPPER LEVELS ARE EXPECTED TO
PREVAIL.

THE CARIBBEAN SEA...
A TROPICAL WAVE IS CROSSING THE DOMINICAN REPUBLIC WITH AXIS
EXTENDING FROM 21N67W TO 14N72W. A LOW HUMIDITY ENVIRONMENT AT
THE LOWER LEVELS IS OBSERVED ACROSS LA HISPANIOLA WEST OF THE
WAVE AXIS AND AHEAD OF THE WAVE IN THE CENTRAL CARIBBEAN.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE HAPPENING NE OF
THE DOMINICAN REPUBLIC ASSOCIATED WITH THE WAVE AND BEING
ENHANCED BY UPPER LEVEL DIFFLUENCE.

UPPER LEVEL DIFFLUENT FLOW FROM A CYCLONIC CIRCULATION OVER THE
FAR WEST CARIBBEAN AND THE BROAD UPPER RIDGE EXTENDING ACROSS
THE REMAINDER OF THE BASIN COMBINED WITH LOWER AND MIDDLE LEVEL
MODERATE TO HIGH MOISTURE SUPPORT A CLUSTER OF MODERATE/STRONG
CONVECTION AND THUNDERSTORMS WITHIN 240 NM OFF THE COAST OF
BELIZE...SIMILAR CONVECTION WITHIN 120 NM OFF THE NICARAGUA
COAST AND ISOLATED THUNDERSTORMS NE OF JAMAICA. CLUSTERS OF
MODERATE/STRONG CONVECTION WITH THUNDERSTORM ACTIVITY CAN BE
FOUND IN THE SOUTHERN CARIBBEAN S OF 12N IN ASSOCIATION WITH THE
MONSOON TROUGH AXIS AND A 1011 MB LOW CLOSE TO THE COAST OF
NORTHERN COLOMBIA.

TRADEWINDS CONTINUE TO SPREAD ACROSS THE BASIN SUBSIDING TO 20
KT OVER THE CENTRAL CARIBBEAN WHILE 10-15 KT WINDS PREVAIL
ELSEWHERE. A TRAILING TROPICAL WAVE IS ENTERING THE EASTERN
CARIBBEAN. SEE THE WAVES SECTION ABOVE FOR A DETAILED
DESCRIPTION OF ITS ENVIRONMENT.

OTHERWISE...THE TROPICAL WAVE OVER LA HISPANIOLA WILL MOVE OUT
OF HAITI BY TUESDAY AFTERNOON AND IS LIKELY TO VANISH IN THE
WAKE OF INTERACTION WITH A VERY DRY ENVIRONMENT AT THE LOWER
LEVELS. THE TRAILING WAVE IS EXPECTED TO MOVE OVER PUERTO RICO
THIS EVENING. MODERATE SHOWERS CAN BE EXPECTED IN ASSOCIATION TO
THIS WAVE. A LOW PRESSURE IS EXPECTED TO DEVELOP OVER THE
SOUTHERN CARIBBEAN BY WEDNESDAY AND HEAVY SHOWERS WILL BE
ASSOCIATED TO IT.

HISPANIOLA...
DRY SURFACE CONDITIONS ARE OVER THE ISLAND W OF 70W WHILE LIGHT
TRADEWINDS OF 5-10 KT CONTINUES. TROPICAL WAVE IS CROSSING THE
DOMINICAN REPUBLIC WITH AXIS EXTENDING FROM 21N67W TO 14N72W. IT
WILL MOVE OUT OF HAITI BY TUESDAY AFTERNOON AND IS LIKELY TO
VANISH IN THE WAKE OF INTERACTION WITH A VERY DRY ENVIRONMENT AT
THE LOWER LEVELS. THE TROPICAL WAVE WITH AXIS CURRENTLY LOCATED
NEAR 57W IS EXPECTED TO ENTER THE DOMINICAN REPUBLIC WEDNESDAY
AFTERNOON GENERATING RAINSHOWERS ACROSS THIS PORTION OF THE
ISLAND.

THE ATLANTIC OCEAN...
BROAD SURFACE RIDGING DOMINATES ACROSS THE BASIN N OF 16N FROM A
SET OF HIGH PRESSURE CENTERS N OF THE AREA OF DISCUSSION. EXCEPT
FOR THE AREAS DISCUSSED ABOVE...TOTAL PRECIPITABLE WATER IMAGERY
SHOW AN OVERALL DRY ENVIRONMENT AT THE LOWER LEVELS WHICH IS
SUPPORTING FAIR WEATHER BASIN WIDE.

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

$$
RAMOS


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