[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141001
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI AUG 14 2015

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
1000 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS IN THE CENTRAL ATLC WITH AXIS NEAR 36W
...MOVING W AT 15 KT OVER THE PAST 24 HOURS. CIRA LAYER
PRECIPITABLE WATER IMAGERY FROM THE SURFACE TO 850 MB SHOW THE
WAVE IS WITHIN A VERY DRY ENVIRONMENT...COINCIDING WITH A
SAHARAN DRY AIR AND DUST AIRMASS AS INDICATED BY ENHANCED
METEOSAT IMAGERY. THERE IS NO CONVECTION ASSOCIATED WITH THIS
WAVE.

A TROPICAL WAVE IS EAST OF THE LESSER ANTILLES WITH AXIS NEAR
58W...MOVING W AT 10-15 KT OVER THE PAST 24 HOURS. THE WAVE IS
ASSOCIATED WITH A MODERATE MOIST ENVIRONMENT FROM THE SURFACE TO
850 MB ACCORDING TO CIRA LAYER PRECIPITABLE WATER IMAGERY.
SAHARAN DRY AIR AND DUST ENGULF THE WAVE...WHICH IS LIMITING THE
CONVECTION TO SCATTERED MODERATE AND ISOLATED TSTMS FROM 10N TO
16N BETWEEN 55W AND 60W.

A TROPICAL WAVE IS MOVING ACROSS CENTRAL AMERICA WITH AXIS NEAR
84W EXTENDING NORTHWARD OVER THE NW CARIBBEAN NEAR 18N. THE WAVE
IS ASSOCIATED WITH A MODERATE MOIST ENVIRONMENT FROM THE SURFACE
TO 850 MB ACCORDING TO CIRA LAYER PRECIPITABLE WATER IMAGERY. AN
UPPER-LEVEL LOW CENTERED W OF JAMAICA NEAR 19N81W ALONG WITH THE
AFOREMENTIONED MOISTURE SUPPORT SCATTERED MODERATE CONVECTION
AND TSTMS WITHIN 175 NM E OF THE WAVE AXIS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH COASTAL AFRICA NEAR 13N16W AND
CONTINUES TO 08N25W TO 08N34W. THE ITCZ BEGINS W OF A TROPICAL
WAVE NEAR 08N37W AND CONTINUES ALONG 08N45W TO 08N52W. OTHER
THAN CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG
58W...ISOLATED SHOWERS AND TSTMS ARE FROM 11N-14N BETWEEN 20W
AND 25W AND FROM 06N TO 10N BETWEEN 27W AND 52W.

...DISCUSSION...

...GULF OF MEXICO...

THE SE PERIPHERY OF A BROAD MIDDLE TO UPPER LEVEL RIDGE CENTERED
BETWEEN SOUTHERN UTAH AND NORTHERN NEW MEXICO COVERS THE CENTRAL
AND WESTERN GULF OF MEXICO WHILE A TROUGH EXTENDS ALONG THE
EASTERN CONUS SW TO A BASE OVER THE NE BASIN. THIS TROUGH ALOFT
CONTINUE TO SUPPORT A STATIONARY FRONT ACROSS NORTHERN FLORIDA
AND A 1015 MB LOW NEAR 27N85W FROM WHICH A SURFACE TROUGH
EXTENDS W-SW TO 24N88W. SCATTERED SHOWERS AND TSTMS ARE FROM 25N
TO 29N E OF 87W. OVER THE SW GULF...A 1016 MB HIGH IS NEAR
23N93W. VARIABLE WINDS OF LESS THAN 15 KT ARE BASIN-WIDE. THE
STATIONARY FRONT WILL DISSIPATE FRIDAY EVENING LEAVING A TROUGH
OF LOW PRESSURE FROM THE NE TO THE CENTRAL GULF DURING THE NEXT
TWO DAYS...POSSIBLE ISOLATED TO SCATTERED SHOWERS WILL ACCOMPANY
THIS AREA OF LOW PRESSURE.

CARIBBEAN SEA...

A TROPICAL WAVE IS MOVING ACROSS CENTRAL AMERICA WITH AXIS
EXTENDING N INTO THE NW CARIBBEAN. CONVECTION ASSOCIATED WITH
THIS WAVE IS OCCURRING MAINLY ALONG THE COASTLINES FROM NICARAGUA
TO NORTHERN PANAMA. SEE TROPICAL WAVES SECTION. A BROAD UPPER-LEVEL
LOW CENTERED W OF JAMAICA IS GENERATING A DIFFLUENT WIND
ENVIRONMENT OVER PORTIONS OF THE NW BASIN...THUS SUPPORTING
SCATTERED SHOWERS AND TSTMS FROM 16N TO 20N BETWEEN 78W AND 82W
AND ISOLATED SHOWERS ACROSS THE WINDWARD PASSAGE. LOW PRESSURE
OVER NW COLOMBIA ENHANCES SCATTERED MODERATE CONVECTION S OF 11N
E OF 80W. SHALLOW MOISTURE IS ACROSS THE REMAINDER BASIN WITH
DRIER CONDITIONS OBSERVED OVER THE E-NE CARIBBEAN. STRONG DEEP
LAYER WIND SHEAR OVER THE CENTRAL AND E CARIBBEAN HINDER THE
DEVELOPMENT CONVECTION AT THIS TIME. NE TO E WINDS OF 20 TO 25
KT ARE FROM 11N TO 14N BETWEEN 72W AND 77W WITH SEAS TO 9 FT.
THE NEXT TROPICAL WAVE WILL APPROACH THE LESSER ANTILLES THIS
EVENING WITH ASSOCIATED SHOWERS AND TSTMS MAINLY AFFECTING THE
WINDWARD ISLANDS.

...HISPANIOLA...

A BROAD UPPER-LEVEL LOW CENTERED W OF JAMAICA IS GENERATING A
DIFFLUENT WIND ENVIRONMENT OVER A PORTION OF THE NW
CARIBBEAN...WHICH ALONG WITH MODERATE SHALLOW MOISTURE SUPPORT
ISOLATED SHOWERS AND TSTMS ACROSS THE WINDWARD PASSAGE. FAIR
WEATHER CONDITIONS ARE EXPECTED THROUGH SUNDAY.

ATLANTIC OCEAN...

A MIDDLE TO UPPER LEVEL TROUGH EXTENDS ALONG THE EASTERN CONUS
SW TO A BASE OVER THE NE GULF OF MEXICO SUPPORTING A STATIONARY
FRONT EXTENDING FROM 30N79W SW TO JACKSONVILLE...THEN W ACROSS
NORTHERN FLORIDA. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM
30N77W SW TO 24N81W SUPPORTING SCATTERED SHOWERS AND TSTMS FROM
25N TO 31N BETWEEN 76W AND 79W. A BROAD SURFACE RIDGE COVERS THE
REMAINDER BASIN AND SUPPORTS FAIR WEATHER. A WEAKNESS IN THE
RIDGE IS ANALYZED AS A 1014 MB LOW NEAR 23N21W...HOWEVER LACKING
CONVECTION. FOR TROPICAL WAVES SEE SECTION ABOVE.

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

$$
NR
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