[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301804
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE JUL 30 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1725 UTC.

...TROPICAL WAVES...
TROPICAL WAVE AXIS EXTENDS FROM 16N35W TO 04N33W MOVING W NEAR 5
KT. IN GENERAL...THE WAVE IS EMBEDDED IN A MODERATE MOIST
ENVIRONMENT WITH A SLIGHTLY MOISTER ENVIRONMENT S OF 07N OR THE
PORTION OF THE WAVE S OF THE MONSOON TROUGH AXIS. ISOLATED
MODERATE CONVECTION IS WITHIN 170 NM EITHER SIDE OF THE WAVE
AXIS IN THIS REGION OF THE WAVE. HOWEVER...N OF 07N THERE IS SAL
DRY AIR SPARSED IN THE WAVE ENVIRONMENT WHICH IS HINDERING
CONVECTION. A SAL OUTBREAK WITH VERY DRY AIR IS JUST BEHIND THIS
WAVE. MODEL GUIDANCE INDICATES THAT DRY AIR INTRUSION FROM THIS
OUTBREAK MAY ACT TO DISSIPATE THE WAVE BY EARLY THURSDAY.

TROPICAL WAVE OR THE REMNANTS OF DORIAN ARE MOVING ACROSS TURKS
AND CAICOS AS WELL AS HAITI. ITS AXIS EXTENDS FROM 24N71W TO
14N73W AND IS MOVING W-NW NEAR 5 KT. THE PORTION OF THE WAVE
OVER THE W ATLC AND HISPANIOLA IS EMBEDDED IN A MODERATE MOIST
ENVIRONMENT WHILE OVER THE CENTRAL CARIBBEAN IT IS EMBEDDED IN
DRY AIR. STRONG DEEP LAYER WIND SHEAR HAS ACTED TO DISPLACE MOST
OF THE CONVECTION ASSOCIATED WITH THIS WAVE NW OF THE AXIS. THIS
CONVECTION IS FROM 21N-26N BETWEEN 67W-70W AND IS DESCRIBED AS
SCATTERED MODERATE. SCATTERED RAINSHOWERS WITH ISOLATED TSTMS
ARE WITHIN 200 NM W OF THE WAVE AXIS FROM 18N-22N.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM THE WEST AFRICAN COAST NEAR
13N16W TO 07N26W 06N37W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 06N37W TO 06N46W 05N52W. BESIDES THE CONVECTION
ASSOCIATED WITH THE WAVE ALREADY DISCUSSED...SCATTERED MODERATE
CONVECTION IS FROM 06N-10N E OF 17W. A CLUSTER OF MODERATE
CONVECTION WITH TSTMS IS FROM 04N-25N BETWEEN 23W-28W. ISOLATED
MODERATE CONVECTION IS WITHIN 100 NM N OF THE MONSOON AXIS
BETWEEN 20W-23W AND WITHIN 80 NM S OF THE ITCZ AXIS BETWEEN 42W-
47W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 1500 UTC...SURFACE RIDGING DOMINATES ACROSS THE GULF WITH
RETURN FLOW IN THE RANGE OF 5-10 KT ANCHORED BY A 1022 MB HIGH
NEAR 27N87W. MODERATE MOISTURE IS BEING ADVECTED TO THE FLORIDA
PENINSULA BY E-SE FLOW OVER THE W ATLC AS WELL AS UPPER LEVEL
NORTHEASTERLY FLOW WHICH COMBINED WITH MIDDLE LEVEL DIFFLUENCE
IS SUPPORTING SCATTERED SHOWERS AND TSTMS S OF 27N INCLUDING THE
FLORIDA STRAITS. A TONGUE OF LOWER AND MIDDLE LEVELS DRY AIR IS
SUPPORTING FAIR WEATHER OVER THE REMAINDER BASIN.

SURFACE RIDGING IS EXPECTED TO CONTINUE ACROSS MOST OF THE BASIN
DURING THE NEXT 48 HOURS AS WELL AS THE CENTER OF HIGH PRESSURE.
RAINSHOWERS ACTIVITY IS EXPECTED TO BE LIMITED DURING THIS
PERIOD SUPPORTED BY UPPER LEVEL RIDGING AS WELL AS FAIRLY DRY
AIR IN THE LOWER TO MIDDLE LEVELS.

CARIBBEAN SEA...
STRONG TRADEWINDS UP TO 25 KT CONTINUE TO SPREAD OVER THE
CENTRAL-SOUTHERN CARIBBEAN WHICH ARE BANKING HIGH LOW LEVEL
MOISTURE ALONG THE SOUTHERN COAST OF NICARAGUA...THE COAST OF
COSTA RICA AND PANAMA W OF 80W. THE MONSOON TROUGH AXIS IS
ENHANCING NUMEROUS MODERATE CONVECTION WITH TSTMS IN THIS REGION
S OF 12N. THE REMNANTS OF DORIAN ARE MOVING ACROSS TURKS AND
CAICOS AS WELL AS HAITI AND IS GENERATING SCATTERED SHOWERS AND
TSTMS OVER CUBA AS WELL AS ISOLATED SHOWERS ACROSS HAITI.
OTHERWISE...LOWER AND MIDDLE LEVEL DRY AIR SUPPORTS FAIR WEATHER
OVER THE REMAINDER BASIN.

THE REMNANTS OF DORIAN ARE EXPECTED TO MOVE ACROSS THE BAHAMAS
LATER TODAY GENERATING MORE SHOWERS.

HISPANIOLA...
MOSTLY DRY AIR IS ACROSS THE HISPANIOLA. ISOLATED SHOWERS ARE
OVER HAITI ASSOCIATED WITH THE REMNANTS OF DORIAN. RAINSHOWERS
ARE EXPECTED TO REFORM LATER THIS AFTERNOON AS WELL AS WEDNESDAY
AFTERNOON/EVENING.

ATLANTIC OCEAN...
THE REMNANTS OF DORIAN ARE MOVING ACROSS TURKS AND CAICOS AS
WELL AS HAITI. STRONG DEEP LAYER WIND SHEAR HAS ACTED TO
DISPLACE MOST OF THE CONVECTION ASSOCIATED WITH THIS NOW TRPCL
WAVE NW OF ITS AXIS. THIS CONVECTION IS FROM 21N-26N BETWEEN 67W-
70W AND IS DESCRIBED AS SCATTERED MODERATE. SCATTERED
RAINSHOWERS WITH ISOLATED TSTMS ARE WITHIN 200 NM W OF THE WAVE
AXIS FROM 18N-22N. THE REMNANTS OF DORIAN ARE ALSO GENERATING
SCATTERED SHOWERS AND TSTMS OFFSHORE AND ALONG THE NORTHERN
COAST OF CUBA WITH ISOLATED SHOWERS ACROSS THE BAHAMAS. AN UPPER
LEVEL LOW IS SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM
26N45W TO 14N48W WITH ISOLATED SHOWERS WITHIN 130 NM W OF ITS
AXIS N OF 21N. A 1024 MB HIGH IS NEAR 30N31W WHICH IS EXPECTED
TO DRIFT WESTWARD WITHIN THE NEXT 24 HOURS. BESIDES THE FEATURES
ALREADY DISCUSSED...SURFACE RIDGING AND MOSTLY DRY AIR IS
SUPPORTING FAIR WEATHER ACROSS THE REMAINING BASIN.

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

$$
NR


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