[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 071156
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN JUL 07 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
1015 UTC.

...SPECIAL FEATURES...
A TROPICAL WAVE EXTENDS FROM 20N37W TO A WEAK 1009 MB SURFACE
LOW NEAR 8N39W MOVING WEST AT 15-20 KT. THE WAVE AXIS IS
EMBEDDED WITHIN A DRY SAHARAN AIR LAYER...WHICH IS LIMITING
CONVECTION NEAR THE MAJORITY OF THE AXIS EXCEPT NEAR THE LOW
CENTER. SCATTERED MODERATE/STRONG CONVECTION IS WEST OF THE LOW
CENTER FROM 6N-11N BETWEEN 40W-44W. THIS SYSTEM HAS A MEDIUM
CHANCE OF DEVELOPMENT INTO A TROPICAL CYCLONE OVER THE NEXT 48
HOURS.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 22N67W TO 11N70W MOVING WEST NEAR 15 KT.
THE WAVE ALIGNS WITH A SURGE OF DEEP LAYER MOISTURE PRESENT IN
TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE CONVECTION
IS WITHIN 75 NM EITHER SIDE OF THE AXIS FROM 17N-22N.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE COAST OF MAURITANIA NEAR
17N16W TO 11N22W 10N28W. THE ITCZ BEGINS NEAR 10N28W AND
CONTINUES ALONG 10N35W 6N44W 2N51W. SCATTERED MODERATE/STRONG
CONVECTION IS FROM 7N-12N BETWEEN 14W-23W.

...DISCUSSION...

GULF OF MEXICO...
MOIST CONDITIONS REMAIN ACROSS MUCH OF THE GULF OF
MEXICO...ESPECIALLY THE NW HALF OF THE BASIN. THIS IS DUE TO A
COMBINATION OF MOIST SOUTHEASTERLY FLOW AT THE SURFACE...AND
MOIST SOUTHWESTERLY FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH
ALONG THE NW GULF COAST...AND AN UPPER LEVEL RIDGE WITH AXIS
FROM 31N84W TO 22N98W. ISOLATED SHOWERS AND POSSIBLE
THUNDERSTORMS ARE NW OF A LINE FROM 31N86W TO 19N96W WITH AN
AREA OF STRONGER ACTIVITY FROM 16N-22N BETWEEN 94W-96W...AND
FROM 23N-27N BETWEEN 93W-98W. A SURFACE TROUGH LINES THE NW GULF
COAST ALONG 30N92W TO 27N97W...WHICH IS HELPING CONTRIBUTE TO
SOME OF THE SHOWERS IN THE AREA. A SECOND SURFACE TROUGH IS BAY
OF CAMPECHE ALONG 22N90W TO 18N93W. THE SURFACE TROUGH IN THE NW
CORNER IS EXPECTED TO DRIFT NW OVER THE NEXT DAY OR SO AS
SURFACE RIDGING BUILDS OVER THE BASIN. MOIST CONDITIONS WILL
REMAIN ACROSS MUCH OF WESTERN GULF FOR AT LEAST THE NEXT 24
HOURS.

CARIBBEAN SEA...
MOISTURE FROM THE GULF OF MEXICO IS BEING DRAWN OVER THE NW
CARIBBEAN IN NORTHERLY FLOW ALOFT AROUND AN UPPER LEVEL RIDGE
OVER THE GULF. ONLY A FEW CLUSTERS OF SHOWERS/THUNDERSTORMS ARE
FROM 18N-21N BETWEEN 78W-87W. STRONG SHOWERS/THUNDERSTORMS ARE
IN THE EXTREME SW CARIBBEAN S OF 11N BETWEEN 76W-84W ASSOCIATED
WITH THE MONSOON TROUGH THAT EXTENDS FROM COSTA RICA TO NORTHERN
COLOMBIA. THE REMAINDER OF THE BASIN IS FAIRLY DRY EXCEPT FOR
ISOLATED SHOWERS OVER THE N CENTRAL CARIBBEAN NORTH OF 17N
BETWEEN 67W-71W ASSOCIATED WITH A TROPICAL WAVE APPROACHING
HISPANIOLA. ALOFT...AN UPPER TROUGH EXTENDS FROM THE WINDWARD
PASSAGE TO HONDURAS...BUT IS ACCOMPANIED BY MOSTLY DRY AIR
ALOFT. UPPER LEVEL RIDGING COVERS THE REMAINDER OF THE BASIN
ALSO ACCOMPANIED BY DRY AIR ALOFT CENTERED OVER THE SOUTHERN
WINDWARD ISLANDS NEAR 12N62W. TRADEWIND FLOW OF 15-20 KT IS
THROUGHOUT MUCH OF THE AREA. THE WAVE IS EXPECTED TO CONTINUE
MOVING WEST WITH LITTLE CHANGE ELSEWHERE.

HISPANIOLA...
ONLY A SMALL AREA OF SHOWERS/THUNDERSTORMS IS OVER THE SE
PORTION OF THE DOMINICAN REPUBLIC WITH THE REMAINDER OF THE
ISLAND EXPERIENCING FAIR CONDITIONS. DRY AIR ALOFT IS HELPING
KEEP CONDITIONS FAIR. HOWEVER...MOISTURE ASSOCIATED WITH A
TROPICAL WAVE THAT HAS REACHED EASTERN DOMINICAN REPUBLIC WILL
IMPACT THE ISLAND INCREASING THE CHANCE OF
SHOWERS/THUNDERSTORMS. THIS WILL MOST LIKELY LEAD TO INCREASED
AFTERNOON CONVECTION.

ATLANTIC OCEAN...
BROAD SURFACE RIDGING DOMINATES THE WEST ATLC AROUND A 1024 MB
HIGH NEAR 32N73W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE
CENTERED NEAR 34N74W. HOWEVER...AN UPPER LEVEL LOW TO THE SOUTH
NEAR 24N70W SUPPORTS A WEAK SURFACE TROUGH NEAR 26N73W TO 23N73W
ALONG WITH A FEW ISOLATED SHOWERS FROM 22N-26N BETWEEN 69W-74W.
A TROPICAL WAVE IS TO THE EAST SUPPORTING A FEW ISOLATED
SHOWERS/THUNDERSTORMS FROM 19N-23N BETWEEN 64W-69W. A
DISSIPATING STATIONARY FRONT TO THE NORTH EXTENDS INTO THE AREA
ALONG 31N43W TO 28N61W SUPPORTING ISOLATED SHOWERS WITHIN 90
NM...AND SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 28N-31N
BETWEEN 40W-43W. THE FRONT IS SUPPORTED BY AN UPPER LEVEL LOW
NEAR 31N41W. THE REMAINDER OF THE BASIN IS DOMINATED BY BROAD
SURFACE RIDGING ANCHORED BY A 1023 MB HIGH NEAR 33NN29W.
ALOFT...UPPER RIDGING DOMINATES THE TROPICAL ATLC CENTERED NEAR
13N61W. A SECOND UPPER RIDGE IS CENTERED NEAR 30N29W. VERY DRY
AIR IS THROUGHOUT THE EAST ATLC DUE TO THE PRESENCE OF A BROAD
SAHARAN AIR LAYER...WHICH IS KEEPING CONDITIONS FAIR ACROSS MUCH
OF THE AREA.

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

$$
WALTON


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