[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 070604
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON JUL 07 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 07N24W TO 13N28W MOVING W AT 15-20
KT. DESPITE THE LOW LATITUDE NATURE OF THE WAVE...WITH THE MID-
LEVEL VORTEX BEING NEAR 08N...THE SYSTEM HAS MAINTAINED AN
IMPRESSIVE SATELLITE PRESENTATION WITH DEEP CONVECTION INTACT
SINCE LEAVING WEST AFRICA ABOUT A DAY PREVIOUS. A 2238Z ASCAT
PASS INDICATED A HIGH AMPLITUDE TROUGH...BUT WITHOUT A CLOSED
CIRCULATION.  SCATTERED MODERATE CONVECTION EXISTS IN
ASSOCIATION WITH THE WAVE FROM 05N-09N BETWEEN 25W-31W.

TROPICAL WAVE EXTENDS FROM 07N39W TO 14N33W MOVING W AT ABOUT 15
KT. A STRONG SAHARAN AIR LAYER SIGNAL IS NOTED ON METEOSAT-9 AND
TOTAL PRECIPITABLE WATER IMAGERY SURROUNDING THE WAVE THAT
CONTINUES TO RESULT IN AN OVERALL LACK OF ANY SIGNIFICANT
CONVECTION AT THIS TIME. DURING THE PAST 24 HOURS...THE WAVE HAS
LIKELY DISPERSED A PORTION OF ITS ENERGY INTO A MID-LATITUDE
AMPLIFIED 700 MB TROUGH WHICH LIES TO THE WEST N OF 12N BETWEEN
35W-42W. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE
AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 10N80W TO 21N77W MOVING W AT 20-25
KT. THE WAVE CONTINUES TO TRACK ACROSS THE WESTERN CARIBBEAN
THIS EVENING AS A BROAD 700 MB TROUGH WITH ENHANCED TOTAL
PRECIPITABLE WATER EAST OF THE TROUGH AXIS.  ISOLATED MODERATE
CONVECTION IS WITHIN 120 NM OF THE AXIS N OF 19N.

TROPICAL WAVE EXTENDS FROM 11N95W IN THE NORTHEASTERN PACIFIC
OCEAN TO 20N93W MOVING W AT 20 KT. THE WAVE IS INDISTINCT AT THE
SURFACE AND IN THE TOTAL PRECIPITABLE WATER IMAGERY...HOWEVER...
IT IS STILL PRESENT IN THE SUNY-ALBANY TROPICAL TROUGH
DIAGNOSTICS AT 700 MB.  THE WAVE IS CURRENTLY MOVING BENEATH AN
UPPER LEVEL SOUTHWESTERLY FLOW PATTERN THAT REMAINS FAIRLY
DIFFLUENT ON THE EASTERN PERIPHERY OF UPPER LEVEL LOW CENTERED
OVER EAST-CENTRAL MEXICO NEAR 23N101W. WHILE SUBSTANTIAL DEEP
CONVECTION OCCURRED OVER SOUTHERN MEXICO EARLIER IN THE DAY...NO
SIGNIFICANT DEEP CONVECTION IS CURRENTLY OCCURRING.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO
06N29W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
06N29W TO 07N40W TO 04N52W ON THE SOUTH AMERICAN COAST. ASIDE
FROM THE CONVECTION ALONG 25-31W ASSOCIATED WITH THE WAVE...NO
SIGNIFICANT DEEP CONVECTION IS NOTED ON SATELLITE IMAGERY AT
THIS TIME.  THE NORTHEAST PACIFIC MONSOON TROUGH EXTENDS ACROSS
CENTRAL AMERICA AND ENTERS THE CARIBBEAN SEA AT 09N83W AND
EXTENDS TO COLOMBIA AT 09N76W.  SCATTERED MODERATE CONVECTION
EXISTS WITHIN 60 NM OF THE TROUGH AXIS.

...DISCUSSION...

GULF OF MEXICO...
A PAIR OF WEAK 1018 MB HIGHS ARE OVER THE GULF OF MEXICO THIS
EVENING AT 27N88W AND 21N97W.  THE RESULTING VERY WEAK PRESSURE
GRADIENT OVER THE GULF IS PRODUCING LIGHT TO GENTLE BREEZE
WINDS.  AN UPPER LEVEL LOW CENTERED OVER EAST-CENTRAL MEXICO
NEAR 23N101W INTERACTING WITH THE AFOREMENTIONED WESTERNMOST
TROPICAL WAVE IS HELPING TO PROMOTE SCATTERED UPPER LEVEL
CLOUDINESS OVER THE SOUTHERN GULF BUT WITH LITTLE DEEP
CONVECTION.  AN UPPER TROUGH OVER THE SOUTHEAST US IS HELPING TO
MAINTAIN A SURFACE TROUGH ALONG THE WEST COAST OF THE FLORIDA
PENINSULA.  MOST OF THE GULF IS COVERED BY SUBSTANTIAL LOW-LEVEL
MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY.
ISOLATED CONVECTION OVER THE GULF MAY OCCUR IN THE NEXT COUPLE
OF DAYS...WITH SUBSTANTIAL DEEP CONVECTION OVER SURROUNDING LAND
AREAS DURING THE AFTERNOON DIURNAL MAXIMUM.

CARIBBEAN SEA...
A MODERATE NORTH-SOUTH PRESSURE GRADIENT IS PRODUCING MODERATE
TO FRESH TRADEWINDS ACROSS MOST OF THE CARIBBEAN WITH STRONG
BREEZE CONDITIONS JUST NORTH OF COLOMBIA AS SEEN IN THE 0248Z
ASCAT SCATTEROMETER PASS.  NO SIGNIFICANT DEEP CONVECTION IS
CURRENTLY OCCURRING ACROSS THE CARIBBEAN.  SUBSTANTIAL LOW-LEVEL
MOISTURE IS PRESENT ACROSS THE CENTRAL CARIBBEAN DUE TO THE
TROPICAL WAVE NEAR 80W.  AS THIS WAVE PROGRESSES WESTWARD DURING
THE NEXT COUPLE OF DAYS...CHANCES FOR DEEP CONVECTION INCREASES
SOME OVER THE WESTERN CARIBBEAN AND DIMINISH OVER THE EASTERN
CARIBBEAN.  A FAIRLY LARGE SAHARAN AIR LAYER WILL OVERSPREAD
MOST OF THE CARIBBEAN WITHIN A FEW DAYS.

...HISPANIOLA...
NO SIGNIFICANT DEEP CONVECTION IS CURRENTLY OCCURRING ACROSS
HISPANIOLA. SUBSTANTIAL LOW-LEVEL MOISTURE IS PRESENT ACROSS THE
CENTRAL CARIBBEAN DUE TO THE TROPICAL WAVE NEAR 80W.  AS THIS
WAVE PROGRESSES WESTWARD DURING THE NEXT COUPLE OF
DAYS...CHANCES FOR DEEP CONVECTION FOR HISPANIOLA ARE HIGHER
THAN TYPICAL ON MONDAY...BUT THEN DIMINISH ON TUESDAY AND FOR
THE NEXT COUPLE OF DAYS. A FAIRLY LARGE SAHARAN AIR LAYER WILL
OVERSPREAD MOST OF THE CARIBBEAN WITHIN A FEW DAYS AND SUPPRESS
THE USUAL LATE AFTERNOON DEEP CONVECTION OVER LAND.

ATLANTIC OCEAN...
A WEAK MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER
VAPOR IMAGERY OVER THE FLORIDA PENINSULA AND ADJACENT SW NORTH
ATLANTIC WATERS NEAR 30N81W. SCATTERED SHOWERS AND THUNDERSTORMS
ARE OCCURRING FROM 30-32N BETWEEN 77W AND 80W.  OTHERWISE...THE
REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF AN
UPPER LEVEL LOW CENTERED NEAR 24N74W WITH WIDELY SCATTERED
SHOWERS AND ISOLATED TSTMS OCCURRING FROM 19N-25N BETWEEN 66W-
73W. FARTHER EAST...SURFACE RIDGING INFLUENCES A MAJORITY OF THE
CENTRAL AND EASTERN ATLC ANCHORED BY A 1027 MB HIGH CENTERED
NEAR 34N29W AND A 1023 MB HIGH CENTERED NEAR 29N53W. A PAIR OF
WEAK SURFACE TROUGHS ARE EMBEDDED WITHIN THE SOUTHERN PERIPHERY
OF THE RIDGE...ONE FROM 22N-30N ALONG 37W AND LARGELY THE
REFLECTION OF AN UPPER LEVEL LOW CENTERED NEAR 31N39W...AND THE
OTHER FROM 23N-30N ALONG 47W. ISOLATED SHOWERS ARE OCCURRING
WITHIN 150 NM EITHER SIDE OF THE WESTERN-MOST TROUGH AXIS.

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

$$
LANDSEA


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