[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131744
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED MAY 13 2015

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
1715 UTC.

...SPECIAL FEATURES...
A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRESSURE ACROSS THE
CENTRAL ATLC AND LOWER PRESSURE ACROSS NORTHWESTERN SOUTH
AMERICA IS GENERATING NEAR GALE TO GALE FORCE WINDS WITHIN CLOSE
PROXIMITY TO THE COAST OF COLOMBIA. THESE CONDITIONS ARE
FORECAST TO CONTINUE THROUGH THURSDAY MORNING. SEE LATEST NWS
HIGH SEAS FORECAST UNDER WMO/AWIPS HEADERS MIAHSFAT2/FZNT02 KNHC
FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO
05N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
05N22W TO 06N30W TO 04N42W TO THE EQUATOR NEAR 51W. SCATTERED
MODERATE CONVECTION IS FROM THE EQUATOR TO 02N BETWEEN 03W-
12W...AND FROM 03N-08N BETWEEN 13W-34W.

...DISCUSSION...

GULF OF MEXICO...
A MID-LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY
OVER SOUTHERN TEXAS WITH THE PARENT UPPER LEVEL TROUGH TO THE NW
OVER NEW MEXICO AND WEST TEXAS. THE TROUGHING SUPPORTS A
STATIONARY FRONT EXTENDING FROM ACROSS THE NEW ORLEANS LOUISIANA
AREA WESTWARD ALONG THE GULF COAST TO GALVESTON BAY THEN INLAND
ACROSS SE TEXAS TO THE RIO GRANDE RIVER NEAR 29N101W. GIVEN AN
OVERALL DIFFLUENT ENVIRONMENT ALOFT OVER THE WESTERN GULF AND
SOUTHERN U.S. PLAINS...AND MOIST CONVERGENT SOUTHEASTERLY
SURFACE FLOW TO THE SOUTH OF THE FRONTAL BOUNDARY...SCATTERED
SHOWERS AND TSTMS ARE OCCURRING WEST OF A LINE FROM 30N92W TO
21N97W...INCLUDING INLAND PORTIONS OF TEXAS AND WESTERN
LOUISIANA. TO THE SOUTH ACROSS THE SW GULF...A SURFACE TROUGH IS
ANALYZED FROM THE MEXICO COAST NEAR 18N94W TO 23N95W AND IS
PROVIDING FOCUS FOR SCATTERED SHOWERS AND TSTMS S OF 21N BETWEEN
94W-96W. OTHERWISE...AN UPPER LEVEL RIDGE AXIS EXTENDING FROM
20N94W TO 29N91W INFLUENCES THE REMAINDER OF THE GULF. NORTHERLY
FLOW ALOFT ON THE EASTERN PERIPHERY OF THE UPPER LEVEL RIDGE IS
PROVIDING OVERALL STABLE CONDITIONS AT THE SURFACE. HOWEVER...
THE SOUTHERN EXTENT OF A SW NORTH ATLC COLD FRONT EXTENDS ACROSS
THE FLORIDA PANHANDLE TO NEAR 29N90W WITH POSSIBLE ISOLATED
SHOWERS OCCURRING WITHIN 90 NM EITHER SIDE OF THE BOUNDARY.
GENTLE TO MODERATE E-SE WINDS ARE EXPECTED TO PREVAIL ACROSS THE
GULF INTO THURSDAY AS THE FRONTAL BOUNDARY GRADUALLY SHIFTS
NORTH OF THE GULF COAST OVERNIGHT. A SURFACE RIDGE IS THEN
EXPECTED RE-ESTABLISH FOR THE UPCOMING WEEKEND.

CARIBBEAN SEA...
ASIDE FROM NEAR GALE TO GALE FORCE CONDITIONS OCCURRING ACROSS
PORTIONS OF THE SW CARIBBEAN OFF THE COAST OF COLOMBIA...BROAD
UPPER LEVEL TROUGHING IS NOTED ON WATER VAPOR IMAGERY OVER THE
SW NORTH ATLC THAT STRETCHES W-SW OVER NW CARIBBEAN WITH WEST-
SOUTHWESTERLY FLOW PREVAILING TO THE EAST OF 80W OVER THE
CENTRAL AND EASTERN CARIBBEAN. OTHERWISE...THE STRONG TRADE
WINDS ARE THE MAIN IMPACT GENERATED BY A STRENGTHENED PRESSURE
GRADIENT BETWEEN A 1028 MB SUBTROPICAL HIGH CENTERED NEAR 30N50W
AND LOWER PRESSURE ACROSS NORTHWESTERN SOUTH AMERICA ANCHORED BY
A 1006 MB LOW CENTERED NEAR 10N76W. THE PRESSURE GRADIENT IS
FORECAST TO RELAX SOMEWHAT BY FRIDAY AS FRONTAL TROUGHING MOVES
ACROSS THE SW NORTH ATLC REGION TO THE N-NE OF THE BASIN.

...HISPANIOLA...
CURRENTLY...RELATIVELY CLEAR SKIES PREVAIL ACROSS THE ISLAND
THIS AFTERNOON...HOWEVER A BROAD UPPER LEVEL TROUGH IS NOTED ON
WATER VAPOR IMAGERY OVER THE SW NORTH ATLC AND NW CARIBBEAN WITH
AXIS FROM 28N65W TO 20N81W PROVIDING FOR MARGINALLY DIFFLUENT
CONDITIONS ALOFT. ISOLATED SHOWERS ARE POSSIBLE DURING THE
AFTERNOON AND EVENING HOURS GIVEN PEAK DAYTIME HEATING AND
INSTABILITY.

ATLANTIC OCEAN...
UPPER LEVEL TROUGHING EXTENDS FROM OVER THE NE CONUS TO THE SE
CONUS SUPPORTING A COLD FRONT EXTENDING FROM OFFSHORE OF THE
CAROLINAS NEAR 35N76W SW TO THE SOUTH CAROLINA/GEORGIA BORDER
NEAR 32N81W. THE FRONT WILL CONTINUE TO MOVE INTO THE SW NORTH
ATLC DISCUSSION AREA THROUGH THURSDAY SKIRTING ALONG 30N WHILE
MOVING EASTWARD AND GRADUALLY WEAKENING. ISOLATED SHOWERS AND
TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE BOUNDARY.
FARTHER EAST...AN UPPER LOW IS CENTERED NEAR 31N60W THAT ANCHORS
BROAD UPPER LEVEL TROUGHING WITH AXIS EXTENDING FROM THE LOW
CENTER SW TO A BASE OVER THE NW CARIBBEAN SEA NEAR 20N80W. THE
TROUGHING SUPPORTS ISOLATED SHOWERS AND TSTMS OCCURRING FROM 22N-
27N BETWEEN 63W-68W. OTHERWISE...THE REMAINDER OF THE CENTRAL
AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE
ANCHORED BY A 1028 MB HIGH CENTERED NEAR 30N51W.

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

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