[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 050552
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI JUL 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 23N28W TO 14N28W MOVING WEST AT 5-10 KT.
THE WAVE IS EMBEDDED WITHIN AN AREA OF INCREASED MOISTURE
PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. A LARGE SAHARAN AIR
LAYER SURROUNDS A GOOD PORTION OF THE WAVE...WHICH IS INHIBITING
ANY DEEP CONVECTION NEAR THE AXIS.

TROPICAL WAVE IS ALONG 18N43W TO 7N55W MOVING WEST NEAR 15 KT.
THE WAVE COINCIDES WITH A LARGE SURGE OF DEEP LAYER MOISTURE
PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. AN ASCAT
SCATTEROMETER PASS INDICATES THAT LOW LEVEL CYCLONIC FLOW IS
AROUND THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS FROM 12N-
14N BETWEEN 48W-51W.

TROPICAL WAVE IS ALONG 21N74W TO 10N75W MOVING WEST THROUGH THE
CENTRAL CARIBBEAN AT 15-20 KT. ONLY A WEAK MOISTURE SIGNAL IS
EVIDENT NEAR THE WAVE WITH MUCH HIGHER MOISTURE CONTENT FARTHER
WEST OVER THE WESTERN CARIBBEAN. DRY AIR IS OVER THE AREA ALOFT
EXCEPT NEAR THE NORTHERN PORTION OF THE WAVE WHERE DIFFLUENT
FLOW IS PRESENT AROUND A NARROW UPPER TROUGH NEAR 77W. ISOLATED
MODERATE CONVECTION IS NEAR THE NORTHERN PORTION OF THE WAVE
FROM 18N-22N BETWEEN 73W-76W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA-BISSAU NEAR
12N16W TO 8N19W 8N30W. THE ITCZ BEGINS NEAR 8N30W AND CONTINUES
ALONG 8N38W 11N45W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 7N-10N BETWEEN 21W-26W.

...DISCUSSION...

GULF OF MEXICO...
MOIST CONDITIONS REMAIN ACROSS MUCH OF THE GULF OF MEXICO. THIS
IS DUE TO A COMBINATION OF MOIST SOUTHERLY FLOW AT THE SURFACE
THROUGHOUT MUCH OF THE AREA...AND MOIST SOUTHWESTERLY AND
DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE
CENTRAL CONUS...AND AN UPPER LEVEL RIDGE OVER THE BASIN
EXTENDING FROM THE BAY OF CAMPECHE NEAR 21N91W TO 31N82W.
ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS ARE MAINLY EAST OF
91W. A WEAK SURFACE TROUGH IS ALSO IN THE BAY OF CAMPECHE FROM
26N92W TO 19N93W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 120 NM TO
EITHER SIDE OF THE AXIS. A SECOND SURFACE TROUGH ALONG THE NW
GULF COAST APPEARS TO HAVE DISSIPATED AS OF 0300 UTC. BROAD
SURFACE TROUGHING WILL REMAIN OVER THE WESTERN GULF WITH
MOISTURE CONTINUING TO FLOW OVER MUCH OF THE BASIN FOR THE NEXT
DAY OR SO.

CARIBBEAN SEA...
MODERATE MOISTURE IS THROUGHOUT THE WESTERN CARIBBEAN INDICATED
BY TOTAL PRECIPITABLE WATER IMAGERY. SOME OF THIS IS MOISTURE
ALOFT THAT IS STREAMING OVER THE AREA IN NORTHERLY FLOW AROUND
AN UPPER LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO. A NARROW
UPPER TROUGH IS TO THE EAST ALONG 78W...WHICH IS PROVIDING
DIFFLUENT FLOW ALOFT OVER THE NE CARIBBEAN. ISOLATED SHOWERS ARE
CURRENTLY OVER CUBA WITH A FEW CLUSTERS OF THUNDERSTORMS TO THE
SOUTH FROM 18N-21N BETWEEN 79W-81W. A TROPICAL WAVE TO THE EAST
ALONG 75W IS ALSO PROVIDING SOME MOISTURE TO THE AREA. A FEW
SHOWERS AND THUNDERSTORMS ARE NEAR THE NORTHERN PORTION OF THE
WAVE OVER EASTERN CUBA AND WESTERN HAITI. DRY AIR ALOFT AROUND
AN INVERTED UPPER TROUGH ALONG 72W IS LIMITING CONVECTION NEAR
THE REMAINDER OF THE WAVE. DRY AIR ALOFT ALSO COVERS THE EASTERN
CARIBBEAN WHERE VERY CLEAR SKIES ARE NOTED. SEVERAL STATIONS IN
THE LESSER ANTILLES ARE REPORTING DUST. TRADEWIND FLOW OF 15-20
KT IS THROUGHOUT MUCH OF THE AREA WITH A SMALL AREA OF 25 KT
WINDS NEAR THE COAST OF COLOMBIA IN THE CENTRAL CARIBBEAN. THE
TROPICAL WAVE IS EXPECTED TO CONTINUE MOVING WEST WHERE MOIST
CONDITIONS WILL REMAIN FOR AT LEAST THE NEXT 24 HOURS.

HISPANIOLA...
A TROPICAL WAKE CONTINUES TO IMPACT WESTERN HAITI. THE AXIS IS
JUST WEST OF THE ISLAND...BUT A FEW SHOWERS/POSSIBLE
THUNDERSTORMS REMAIN OVER THE SW CORNER. DRIER AIR IS BEGINNING
TO MOVE OVER THE AREA AS THE WAVE TRACKS WEST...WHICH WILL KEEP
CONVECTION TO A MINIMUM EXCEPT DURING PEAK DAYTIME HEATING WHERE
AFTERNOON ACTIVITY WILL STILL LIKELY OCCUR. A DRIER AIRMASS WILL
CONTINUE TO IMPACT THE ISLAND UNTIL THE NEXT TROPICAL WAVE
APPROACHES EARLY NEXT WEEK.

ATLANTIC OCEAN...
BROAD SURFACE RIDGING DOMINATES THE WEST ATLC AROUND A 1027 MB
HIGH NEAR 34N67W. THE RIDGE IS SUPPORTED BY BROAD UPPER RIDGING
CENTERED NEAR 36N69W. HOWEVER...A NARROW UPPER TROUGH ALONG 79W
IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS OFF THE COAST OF
FLORIDA WEST OF 77W. AN UPPER LEVEL LOW IS CENTERED NEAR 22N58W
SUPPORTING A FEW POSSIBLE SHOWERS FROM 24N-29N BETWEEN 57W-62W.
A DISSIPATING COLD FRONT ALSO EXTENDS INTO THE AREA ALONG 30N50W
TO 27N59W. NO SHOWERS ARE ASSOCIATED WITH THE BOUNDARY. THE
REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A
1026 MB AZORES HIGH NEAR 41N23W. BROAD UPPER RIDGING COVERS THE
TROPICAL ATLC CENTERED NEAR 16N24W. AN UPPER LOW IS TO THE NORTH
NEAR 34N19W...BUT IS NOT CAUSING ANY ACTIVE WEATHER IN THE AREA.
VERY DRY AIR IS THROUGHOUT THIS AREA DUE TO THE PRESENCE OF A
BROAD SAHARAN AIR LAYER.

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

$$
WALTON

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