[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 130542
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN OCT 13 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
0515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 13N68W TO 21N67W MOVING W AT 15-20
KT. THE WAVE LIES BENEATH RELATIVELY DRY AIR ALOFT WITHIN WEAK
ANTICYCLONIC FLOW WITH VERY LITTLE CONVECTION NOTED ON SATELLITE
IMAGERY AT THIS TIME. WATER VAPOR IMAGERY ALSO INDICATES AS THE
WAVE CONTINUES WEST THAT IT WILL LIE BENEATH INCREASED SOUTH-
SOUTHWESTERLY UPPER LEVEL DIFFLUENT FLOW...HOWEVER UNDER
INCREASING WIND SHEAR AS WELL. ANY SIGNIFICANT DEEP CONVECTION
IS LACKING THIS EVENING AS MOST OF THE OVERALL CONVECTIVE
ACTIVITY IS FOUND ACROSS THE CENTRAL CARIBBEAN SEA AND PORTIONS
OF THE SW NORTH ATLC IN ASSOCIATION WITH AN UPPER LEVEL LOW
CENTERED NEAR 17N80W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO
08N31W TO A 1010 MB LOW CENTERED NEAR 12N44W. THE INTERTROPICAL
CONVERGENCE ZONE AXIS EXTENDS FROM 12N44W TO 10N61W. SCATTERED
MODERATE AND ISOLATED STRONG CONVECTION IS FROM 04N-10N BETWEEN
11W-16W. SCATTERED MODERATE CONVECTION IS FROM 10N-14N BETWEEN
23W-33W...FROM 09N-15N BETWEEN 39W-47W...AND FROM 11N-13N
BETWEEN 48W-56W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED
OVER NE MEXICO NEAR 23N99W THAT IS PROVIDING THE GULF BASIN WITH
NORTHWEST TO NORTHERLY FLOW ALOFT THIS EVENING. WATER VAPOR
IMAGERY INDICATES THE FLOW IS MOSTLY DRY AIR AND VERY STABLE
RESULTING IN MOSTLY CLEAR SKIES AND FAIR CONDITIONS AT THE
SURFACE. A 1019 MB HIGH CENTERED IN THE NE GULF WATERS NEAR
29N87W FURTHER PROMOTES THE FAIR CONDITIONS WITH ONLY A FEW
ISOLATED SHOWERS AND TSTMS OCCURRING ALONG THE GULF COAST FROM
28N-31N BETWEEN 89W-94W. SURFACE RIDGING IS EXPECTED TO REMAIN
ACROSS THE GULF THROUGH LATE WEDNESDAY WHEN THE NEXT FRONTAL
BOUNDARY IS FORECAST TO EMERGE OFF THE TEXAS GULF COAST.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS CENTERED NEAR 17N80W AND EXTENDS A TROUGH
AXIS SW TO NEAR 10N84W. WEST OF THE TROUGH AXIS...WATER VAPOR
IMAGERY INDICATES VERY DRY AND STABLE AIR WITHIN NORTH-
NORTHEASTERLY FLOW PROVIDING FOR RELATIVELY QUIET CONDITIONS
THIS EVENING N OF 16N W OF 81W. HOWEVER THE REMAINDER OF THE
CENTRAL AND SW CARIBBEAN COMES UNDER THE INFLUENCE OF THE UPPER
LEVEL LOW AND THE ASSOCIATED LIFTING DYNAMICS WHICH CONTINUE TO
GENERATE SCATTERED SHOWERS AND ISOLATED TSTMS BETWEEN 70W-80W
AND S OF 15N BETWEEN 80W-84W. FARTHER EAST...A WEAK TROPICAL
WAVE IS ANALYZED ALONG 68W IMPACTING THE EASTERN CARIBBEAN WITH
ISOLATED SHOWERS ACROSS THE LESSER ANTILLES BETWEEN 58W-64W AND
IN THE VICINITY OF THE WAVE WITHIN 120 NM EITHER SIDE OF THE
AXIS.

HISPANIOLA...
CURRENTLY THE ISLAND FALLS WITHIN AN AREA OF MIDDLE TO UPPER
LEVEL DIFFLUENCE NOTED TO THE EAST OF AN UPPER LEVEL LOW
CENTERED NEAR 17N80W. THE ADVECTION OF MOISTURE FROM THE EAST
PACIFIC NEAR THE BASE OF THE TROUGHING AND MOISTURE FROM
NORTHERN SOUTH AMERICA NORTHWARD ACROSS THE CENTRAL CARIBBEAN
SEA AND SW NORTH ATLC IS PROVIDING FOR ISOLATED SHOWERS AND
TSTMS THIS EVENING. AS THE UPPER LEVEL LOW IS FORECAST TO
EVENTUALLY DRIFT SOUTHWEST BY LATE SUNDAY INTO MONDAY...UNTIL
THEN HISPANIOLA WILL LIKELY REMAIN IN AN UPPER LEVEL DIFFLUENT
PATTERN WITH INCREASED PROBABILITY OF ISOLATED SHOWERS AND
TSTMS. OF COURSE AS ALWAYS WITH PEAK DAYTIME HEATING AND
INSTABILITY...MAXIMUM AREAL COVERAGE OF CONVECTION IS LIKELY TO
OCCUR IN THE AFTERNOON AND EVENING HOURS. THE ADDITION OF A
TROPICAL WAVE CURRENTLY ALONG 68W WILL ALSO INCREASE LOW-LEVEL
MOISTURE CONVERGENCE AND ENHANCE ANY CONVECTION THROUGH MONDAY.

ATLANTIC OCEAN...
A MID-LEVEL LOW IS CENTERED OFFSHORE OF THE MID-ATLC STATES NEAR
35N74W THAT SUPPORTS AN OCCLUDED 1014 MB LOW CENTERED NEAR
34N74W. A SURFACE TROUGH EXTENDS FROM THE LOW INTO THE
DISCUSSION AREA NEAR 32N75W TO 31N78W GENERATING ISOLATED
SHOWERS WITHIN 75 NM EITHER SIDE OF THE BOUNDARY. FARTHER
EAST...PLENTY OF MIDDLE TO UPPER LEVEL MOISTURE ADVECTION IS
NOTED ON WATER VAPOR IMAGERY EAST OF THE UPPER LEVEL TROUGH AXIS
EXTENDING FROM 34N73W TO THE UPPER LEVEL LOW CENTERED IN THE
WESTERN CARIBBEAN SEA NEAR 17N80W. WIDELY SCATTERED SHOWERS AND
ISOLATED TSTMS ARE OCCURRING WITHIN 210 NM EITHER SIDE OF A LINE
FROM 32N65W TO 20N75W FOCUSED IN THE VICINITY OF MAXIMUM LOW-
LEVEL MOISTURE CONVERGENCE ALONG A SURFACE TROUGH ANALYZED FROM
EASTERN CUBA NEAR 20N76W TO 29N69W. A STATIONARY FRONT EXTENDS
NORTHEAST FROM THE SURFACE TROUGH TO 32N61W. ANOTHER WAVE OF LOW-
LEVEL MOISTURE ROUNDING CENTRAL ATLC RIDGING IS ALIGNED ALONG AN
ARC FROM 25N59W TO 19N63W TO 13N59W WITH EMBEDDED ISOLATED
SHOWERS OCCURRING WITHIN 120 NM EITHER SIDE OF THE ARC.
FINALLY...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER
THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH
CENTERED NEAR 35N27W AND A 1024 MB HIGH CENTERED NEAR 35N13W.
BRIDGING BOTH OF THESE HIGH CENTERS IS A STATIONARY FRONT\
ANALYZED FROM 33N22W TO 31N26W. ISOLATED SHOWERS ARE OCCURRING
WITHIN 90 NM EITHER SIDE OF THE FRONT.

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

$$
HUFFMAN


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