[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 140606
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0545 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS IN THE CENTRAL ATLC WITH AXIS NEAR 35W
...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 THE
PRESENCE OF SAHARAN DRY AIR AND DUST AS INDICATED BY ENHANCED
METEOSAT IMAGERY. THERE IS NO CONVECTION ASSOCIATED WITH THIS
WAVE.

A TROPICAL WAVE IS E-SE OF THE LESSER ANTILLES WITH AXIS NEAR
56W...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 ISOLATED MODERATE FROM 10N TO 15N BETWEEN 53W AND
59W.

A TROPICAL WAVE IS MOVING ACROSS CENTRAL AMERICA WITH AXIS NEAR
83W 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 18N81W ALONG WITH THE
AFOREMENTIONED MOISTURE SUPPORT ISOLATED SHOWERS AND TSTMS
WITHIN 120 NM E OF THE WAVE AXIS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH COASTAL AFRICA NEAR 13N16W AND
CONTINUES TO 09N23W TO 08N33W. THE ITCZ BEGINS W OF A TROPICAL
WAVE NEAR 08N36W AND CONTINUES ALONG 08N45W TO 09N54W. OTHER
THAN CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG
56W...ISOLATED MODERATE CONVECTION IS FROM 10N-14N E OF 23W AND
FROM 04N TO 10N BETWEEN 28W 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
SUPPORTS A STATIONARY FRONT ACROSS NORTHERN FLORIDA AND A 1015
MB LOW NEAR 27N85W FROM WHICH A SURFACE TROUGH EXTENDS W-SW TO
24N89W TO 23N94W. SCATTERED SHOWERS AND TSTMS ARE FROM 24N TO
28N E OF 84W. OVER THE SW GULF...A 1016 MB HIGH IS NEAR 23N95W.
VARIABLE WINDS OF LESS THAN 15 KT ARE BASIN-WIDE. THE STATIONARY
FRONT WILL DISSIPATE FRIDAY MORNING 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 BETWEEN EASTERN CUBA AND WESTERN HISPANIOLA WHERE
SCATTERED SHOWERS AND TSTMS  ARE OBSERVED N OF 17N...INCLUDING THE
WINDWARD PASSAGE. LOW PRESSURE OVER NW COLOMBIA ENHANCES
CONVECTION OVER THE SW BASIN 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 13N
BETWEEN 70W AND 77W WITH SEAS TO 9 FT. WINDS OF 20 KT OR LESS
ARE FROM 13N TO 15N BETWEEN 71W AND 75W WITH SEAS TO 8 FT IN E
SWELL. THE NEXT TROPICAL WAVE WILL APPROACH THE LESSER ANTILLES
FRIDAY 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 BETWEEN EASTERN CUBA AND WESTERN
HISPANIOLA WHERE SCATTERED SHOWERS AND TSTMS ARE OBSERVED N OF
17N...INCLUDING THE WINDWARD PASSAGE. SHOWER ACTIVITY IS
EXPECTED THROUGH LATER THIS MORNING.

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 30N78W SW TO JACKSONVILLE...THEN W ACROSS
NORTHERN FLORIDA. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM
29N78W SW TO 24N82W SUPPORTING SCATTERED SHOWERS AND TSTMS FROM
25N TO 30N BETWEEN 77W AND 80W. A BROAD SURFACE RIDGE COVERS THE
REMAINDER BASIN AND SUPPORTS FAIR WEATHER. A WEAKNESS IN THE
RIDGE IS ANALYZED AS A 1012 MB LOW NEAR 23N19W WITH ASSOCIATED
TROUGH...HOWEVER LACKING CONVECTION. FOR TROPICAL WAVES SEE SECTION
ABOVE.

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

$$
NR
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