[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 190557
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT MON SEP 19 2011

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.

...SPECIAL FEATURES...

A 1008 MB LOW IS EMBEDDED ALONG THE MONSOON TROUGH AXIS NEAR
12N37W. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT
LOW-LEVEL MOISTURE IS MAXIMIZED FROM 06N-14N BETWEEN 33W-40W.
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM
07N-14N BETWEEN 35W-39W. ENVIRONMENTAL CONDITIONS REMAIN
FAVORABLE FOR THE DEVELOPMENT OF A TROPICAL DEPRESSION DURING
THE NEXT COUPLE OF DAYS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO
A 1011 MB LOW NEAR 11N28W TO THE SPECIAL FEATURES 1008 MB LOW
NEAR 12N37W TO 09N48W. SCATTERED MODERATE AND ISOLATED STRONG
CONVECTION IS FROM 11N-13N BETWEEN 25W-30W. SCATTERED MODERATE
CONVECTION IS FROM 04N-07N BETWEEN 22W-30W...AND FROM 05N-11N
BETWEEN 30W-33W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE
WESTERN GULF NEAR 23N93W AND CONTINUES TO SUPPORT A SURFACE
RIDGE AXIS EXTENDING FROM THE SE CONUS OVER GEORGIA THROUGH
28N90W IN THE NORTH-CENTRAL GULF TO THE EAST-CENTRAL MEXICO
COAST NEAR 22N98W. PRIMARILY E TO SE SURFACE WINDS IN THE RANGE
OF 10-15 KT WERE NOTED ON EARLIER ASCAT PASSES AND THESE WINDS
ARE EXPECTED TO PERSIST THROUGH THE OVERNIGHT HOURS. WATER VAPOR
IMAGERY SHOWS AN UPPER LEVEL SHORTWAVE TROUGH PROGRESSING ACROSS
THE CENTRAL AND SOUTHERN U.S. PLAINS WHICH SUPPORTS A COLD FRONT
EXTENDING FROM EASTERN OKLAHOMA INTO NORTH AND CENTRAL PORTIONS
OF TEXAS. THIS FRONT IS FORECAST TO ENTER NW PORTIONS OF THE
GULF EARLY TUESDAY AND BEGIN TO STALL...WHILE A REINFORCING
FRONT WILL IMPACT THE NORTHERN GULF BY THURSDAY. OTHERWISE...A
FEW AREAS OF ISOLATED SHOWERS AND TSTMS ARE ACROSS THE
GULF...ONE NORTH OF THE LOWER FLORIDA KEYS NEAR 25N82W AND
ANOTHER AREA WEST OF THE YUCATAN PENINSULA S OF 21N BETWEEN
90W-93W.

CARIBBEAN SEA...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE
WESTERN CARIBBEAN NEAR 13N81W AND IS PROVIDING AN UPPER LEVEL
DIFFLUENT ENVIRONMENT W OF 74W WITH SCATTERED SHOWERS AND TSTMS
FOCUSED NEAR A SURFACE TROUGH ANALYZED FROM CENTRAL COSTA RICA
NEAR 10N84W TO EASTERN HONDURAS NEAR 15N84W. LOW-LEVEL SPEED
CONVERGENCE OF EASTERLY TRADES ARE GENERATING ISOLATED SHOWERS S
OF 19N W OF 80W. E OF 74W...AN UPPER LEVEL TROUGH EXTENDS FROM
THE SW NORTH ATLC SOUTHWARD TO A BASE OVER NE VENEZUELA. MIDDLE
TO UPPER LEVEL MOISTURE CONTINUES TO BE ADVECTED ACROSS THE MUCH
OF THE NE CARIBBEAN WITH ISOLATED SHOWERS AND TSTMS OCCURRING
OVER THE EASTERN CARIBBEAN E OF 67W. THE UPPER LEVEL TROUGHING
WILL BROADEN OUT THROUGH LATE TUESDAY OVER THE SW NORTH ATLC
PROVIDING THE EASTERN AND CENTRAL CARIBBEAN WITH CONTINUED WEST-
SOUTHWESTERLY FLOW AND HIGHER POSSIBILITY FOR WIDELY SCATTERED
SHOWERS AND ISOLATED TSTMS THROUGH WEDNESDAY.

ATLANTIC OCEAN...
AN UPPER LEVEL SHORTWAVE TROUGH IS PROGRESSING OVER THE WESTERN
NORTH ATLC WITH AXIS ALONG 70W THAT SUPPORTS A COLD FRONT
EXTENDING INTO THE DISCUSSION AREA NEAR 32N74W TO 31N77W WHERE
THE FRONT BECOMES MORE DIFFUSE AS A DISSIPATING STATIONARY FRONT
TO THE FLORIDA PENINSULA NEAR DAYTONA BEACH. SCATTERED SHOWERS
AND ISOLATED TSTMS ARE OCCURRING WITHIN 90 NM N AND 180 NM S OF
THE FRONT. FARTHER TO THE SE...WATER VAPOR IMAGERY INDICATES AN
UPPER LEVEL LOW IS CENTERED NEAR 23N66W. MIDDLE TO UPPER LEVEL
MOISTURE CONTINUES TO STREAM NORTHWARD ON THE EASTERN PERIPHERY
OF THE LOW WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS
OCCURRING OVER THE AREA FROM 19N-26N BETWEEN 62W-71W. ISOLATED
SHOWERS ARE ALSO OCCURRING EAST OF THE LESSER ANTILLES FROM
13N-19N BETWEEN 59W-61W. THE REMAINDER OF THE CENTRAL AND
EASTERN ATLC IS UNDER THE INFLUENCE OF A BROAD UPPER LEVEL
TROUGH DIPPING SOUTHWARD TO 15N BETWEEN 27W-45W. THIS TROUGH
SUPPORTS A SURFACE TROUGH EXTENDING INTO THE DISCUSSION AREA
NEAR 32N39W TO 27N45W WITH ISOLATED SHOWERS AND TSTMS OCCURRING
N OF 27N BETWEEN 30W-41W. FARTHER SOUTH...A WEAK 1012 MB LOW IS
CENTERED NEAR 17N46W THAT EXHIBITS A SMALL AREA OF SCATTERED
MODERATE TO STRONG CONVECTION WITHIN 90 NM OF THE NORTHERN
SEMICIRCLE. THIS LOW IS FORECAST TO CONTINUE DRIFTING WESTWARD
OVER THE NEXT 24-36 HOURS.

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

$$
HUFFMAN




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