[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 042348
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI JUL 04 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...
HURRICANE ARTHUR IS CENTERED NEAR 40.3N 69.6W AT 05/0000 UTC OR
ABOUT 80 NM SSE OF CHATHAM MASSACHUSETTS AND ABOUT 260 NM SW OF
YARMOUTH NOVA SCOTIA MOVING NE AT 24 KT. ESTIMATED MINIMUM
CENTRAL PRESSURE IS 976 MB. MAXIMUM SUSTAINED WIND SPEED IS 70
KT WITH GUSTS TO 85 KT. SCATTERED TO NUMEROUS MODERATE
CONVECTION IS FROM 36N-44N BETWEEN 67W-73W. SEE LATEST
INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/
WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO
HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 09N26W TO 19N22W MOVING W AT 20 KT. A
STRONG SAHARAN AIR LAYER SIGNAL IS NOTED ON METEOSAT-9 IMAGERY
TO THE WEST AND NORTH OF THE WAVE THAT CONTINUES TO RESULT IN AN
OVERALL LACK OF ANY SIGNIFICANT CONVECTION IN THE VICINITY OF
THE WAVE AXIS AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 08N54W TO 19N55W MOVING W AT 15-20
KT. THE WAVE IS RELATIVELY EASY TO IDENTIFY ON THE LAST VISIBLE
GOES-E SATELLITE IMAGERY OF THE DAY. THERE IS NO SIGNIFICANT
DEEP CONVECTION OCCURRING AT THIS TIME WITH THE WAVE DUE TO THE
WAVE REMAINING EMBEDDED WITHIN A STRONG SAHARAN AIR LAYER.

TROPICAL WAVE EXTENDS FROM 09N75W TO 18N73W MOVING W AT 15-20
KT. THE WAVE HAS FRACTURED ENERGY OFF TO THE N-NE AS A SURFACE
TROUGH IS ANALYZED FROM 21N71W TO 24N69W. OTHERWISE...THE WAVE
IS CURRENTLY MOVING BENEATH THE WESTERN PERIPHERY OF AN UPPER
LEVEL LOW CENTERED NEAR 16N73W. DUE TO THE RELATIVELY STABILITY
OF THE NORTHERLY UPPER LEVEL FLOW AND DRY CONDITIONS SURROUNDING
THE WAVE AXIS...NO SIGNIFICANT CONVECTION IS OCCURRING WITH THE
WAVE AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 11N94W TO 21N93W MOVING W AT 15 KT.
THE WAVE IS MOVING THROUGH AN AREA OF FAVORABLE MIDDLE TO UPPER
LEVEL DYNAMICS AS THE BASE OF AN UPPER LEVEL TROUGH IS OVER
SOUTHERN MEXICO NEAR 19N97W TO THE WEST OF THE WAVE AXIS.
SCATTERED MODERATE CONVECTION IS FROM 14N-21N BETWEEN 91W-95W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO
08N26W TO 08N34W TO 07N37W. THE INTERTROPICAL CONVERGENCE ZONE
AXIS EXTENDS FROM 07N37W TO 05N43W TO 05N52W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 03N-12N BETWEEN 06W-15W...AND FROM
05N-10N BETWEEN 17W-32W.

...DISCUSSION...

GULF OF MEXICO...
A WEAKENING MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION IS FOCUSED
OVER THE NW GULF NEAR 28N94W WITH AXIS EXTENDING SOUTHWARD ALONG
96W TO A BASE OVER SOUTHERN MEXICO NEAR 19N97W. BROAD RIDGING
ALOFT PREVAILS TO THE SE OVER THE YUCATAN PENINSULA AND SE GULF
WATERS PROVIDING MOSTLY SOUTHWESTERLY WINDS ALOFT FOR MOST OF
THE GULF THIS EVENING. AT THE SURFACE...A DISSIPATING STATIONARY
FRONT EXTENDS FROM SOUTHEASTERN GEORGIA W-SW TO COASTAL
LOUISIANA NEAR 29N93W AND A SURFACE TROUGH EXTENDS FROM THE
FRONT ACROSS NORTHERN FLORIDA SW TO 26N90W. THE FRONT IS
PROVIDING LOW-LEVEL FOCUS FOR ISOLATED SHOWERS AND TSTMS
OCCURRING N OF 27N BETWEEN 90W-94W. ACROSS THE SW GULF...GIVEN
THE FAVORABLE DIFFLUENT ENVIRONMENT ASSOCIATED WITH THE BASE OF
THE UPPER LEVEL TROUGH...A SURFACE TROUGH ANALYZED FROM 19N95W
TO 24N97W AND A TROPICAL WAVE S OF 21N ALONG 93W ARE GENERATING
SCATTERED SHOWERS AND TSTMS S OF 24N BETWEEN 91W-97W. LOOKING
AHEAD...THE SURFACE TROUGH IS EXPECTED TO REMAIN FAIRLY
STATIONARY ACROSS THE EASTERN GULF WATERS THROUGH EARLY SUNDAY
AND THEN DISSIPATE AS A SURFACE RIDGE BUILDS IN LATE SUNDAY INTO
MONDAY. THE TROPICAL WAVE WILL CONTINUE MOVING WESTWARD AND
LARGELY IMPACT THE SOUTHERN COAST OF MEXICO AND THE ADJACENT
EAST PACIFIC COASTAL WATERS DURING THE WEEKEND.

CARIBBEAN SEA...
UPPER LEVEL ANTICYCLONIC FLOW PREVAILS OVER THE WESTERN
CARIBBEAN W OF 80W...WITH A FAIRLY AMPLIFIED MIDDLE TO UPPER
LEVEL TROUGH AND ASSOCIATED LOW CENTERED NEAR 16N73W. THE LOW
EXTENDS A TROUGH AXIS SOUTHWARD TO A BASE OVER NORTHERN COLOMBIA
NEAR 09N74W. RESULTING SOUTHERLY WINDS ALOFT ARE NOTED OVER THE
EASTERN CARIBBEAN E OF 72W. AT THE SURFACE...MODERATE EASTERLY
TRADE WIND FLOW IS NOTED IN GENERALLY FAIR SKIES THIS EVENING.
SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ACROSS
PORTIONS OF HISPANIOLA AND CUBA DUE TO PEAK DAYTIME HEATING...
INSTABILITY...AND OROGRAPHICALLY FAVORED AREAS.

...HISPANIOLA...
CURRENTLY A FEW ISOLATED SHOWERS ARE OCCURRING ACROSS INTERIOR
PORTIONS OF HISPANIOLA HOWEVER THIS ACTIVITY IS FORECAST TO
GRADUALLY DIMINISH WITH THE LOSS OF DAYTIME HEATING AND
INSTABILITY. THE PRESENCE OF AN UPPER LOW CENTERED 16N73W WILL
KEEP THE ISLAND IN A FAVORABLE ENVIRONMENT ALOFT TO SUPPORT ANY
CONVECTION THAT DOES INITIATE THROUGH THE WEEKEND.

ATLANTIC OCEAN...
MIDDLE TO UPPER LEVEL TROUGHING IS NOTED ON WATER VAPOR IMAGERY
OVER THE EASTERN CONUS AND ALONG THE EASTERN SEABOARD THIS
EVENING THAT SUPPORTS A COLD FRONT EXTENDING FROM 32N78W SW TO
THE GEORGIA COAST NEAR 31N81W. ISOLATED SHOWERS ARE OCCURRING N
OF 28N W OF 72W...WITH STRONGER SCATTERED SHOWERS AND TSTMS
OCCURRING ACROSS INLAND PORTIONS OF THE THE FLORIDA PENINSULA
AND ADJACENT COASTAL WATERS W OF 79W. OTHERWISE...A MIDDLE TO
UPPER LEVEL ANTICYCLONE IS CENTERED OVER BERMUDA NEAR 32N65W
THAT IS SUPPORTIVE OF A SURFACE RIDGE EXTENDING FROM A 1026 MB
HIGH CENTERED NEAR 32N57W SW TO 27N70W TO THE FLORIDA STRAITS.
ONLY A FEW ISOLATED SHOWERS ARE OCCURRING FROM 25N-30N BETWEEN
65W-70W. FARTHER EAST...THE REMAINDER OF THE CENTRAL AND EASTERN
ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A
1032 MB HIGH CENTERED W OF THE AZORES NEAR 39N42W. THE ONLY
SIGNIFICANT WEAKNESS IN THE RIDGE IS A SURFACE TROUGH ANALYZED
FROM 32N54W SW TO 29N59W TO 25N61W. ISOLATED SHOWERS ARE
OCCURRING WITHIN 90 NM EAST OF THE SURFACE TROUGH AXIS.

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

$$
HUFFMAN


This weather bulletin was brought to you by:
www.nashvilleweather.net