[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201731
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI JUL 20 2012

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
1645 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 08N53W TO 17N47W MOVING W AT 15 KT.
CYCLONIC TURNING IS EVIDENT IN THE LOW-LEVEL CLOUD FIELD IN THE
VICINITY OF THE WAVE AXIS BETWEEN 45W-54W. EASTERLY UPPER LEVEL
FLOW DOMINATES ALOFT OVER THE WAVE AS IT REMAINS FAIRLY FREE OF
MOISTURE IN THE MIDDLE AND UPPER LEVEL. POSSIBLE ISOLATED
SHOWERS ARE FROM 09N-16N BETWEEN 45W-52W.

TROPICAL WAVE EXTENDS FROM 14N72W TO 22N75W MOVING W AT 15 KT.
LARGELY EMBEDDED WITHIN THE CLIMATOLOGICAL CYCLONIC CIRCULATION
ACROSS NORTHERN COLOMBIA...THE WAVE DOES EXHIBIT BROAD CYCLONIC
TURNING ACROSS THE CENTRAL CARIBBEAN. IT CONTINUES MOVING INTO A
MORE FAVORABLE DIFFLUENT AREA AS AN UPPER LEVEL LOW IS CENTERED
OVER THE NW CARIBBEAN SEA NEAR 19N78W. LOW-LEVEL MOISTURE
CONVERGENCE ALONG WITH THE AMPLE MIDDLE TO UPPER LEVEL
DIFFLUENCE IS GENERATING SCATTERED MODERATE CONVECTION FROM
15N-17N BETWEEN 68W-73W...AND FROM 16N-20N BETWEEN 75W-80W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N17W TO
12N31W TO 08N39W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 08N39W TO 07N45W TO 10N51W. SCATTERED MODERATE
CONVECTION IS FROM 07N-09N BETWEEN 11W-16W...AND FROM 09N-12N
BETWEEN 16W-21W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR
IMAGERY OVER THE MISSISSIPPI RIVER DELTA REGION IN THE VICINITY
OF 30N89W. THIS UPPER LEVEL TROUGHING IS SUPPORTING A SURFACE
TROUGH ANALYZED FROM MOBILE BAY NEAR 30N88W TO 29N91W. MOSAIC
DOPPLER RADAR IMAGERY AND LIGHTNING DATA INDICATE WIDESPREAD
SHOWERS AND SCATTERED TSTMS ARE OCCURRING N OF 26N BETWEEN
84W-93W. OTHERWISE...THE REMAINDER OF THE GULF IS UNDER THE
INFLUENCE OF NE FLOW ALOFT ON THE SOUTHEASTERN PERIPHERY OF AN
UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED EAST OF THE
TROUGHING NEAR 29N94W. THIS UPPER LEVEL RIDGING SUPPORTS A
SURFACE RIDGE ACROSS THE WESTERN GULF ANCHORED BY A 1019 MB HIGH
CENTERED NEAR 27N93W. THE RIDGE AXIS EXTENDS ALONG 27N INTO THE
SW NORTH ATLC REGION AS WELL AS TO THE SOUTHWEST WHERE A 1020 MB
HIGH IS CENTERED OVER COASTAL EAST-CENTRAL MEXICO NEAR 21N98W.
ISOLATED SHOWERS AND TSTMS ARE OCCURRING OVER THE WESTERN BAY OF
CAMPECHE S OF 21N W OF 95W WHERE LOW-LEVEL MOISTURE CONVERGENCE
IS MAXIMIZED. FINALLY...A BROAD UPPER LEVEL LOW IS CENTERED OVER
THE NW CARIBBEAN SEA NEAR 20N78W AND IS PROVIDING ISOLATED
SHOWERS TO THE FLORIDA STRAITS AND SE GULF S OF 25N BETWEEN
80W-86W. THE RIDGE AXIS IS FORECAST TO SLIDE NORTHWARD BY SUNDAY
AND LOCATE ALONG 30N WITH LIGHT EAST-SOUTHEASTERLY WINDS
PREVAILING INTO EARLY NEXT WEEK.

CARIBBEAN SEA...
AS MENTIONED ABOVE...A TROPICAL WAVE IS PROGRESSING WESTWARD
ACROSS THE CENTRAL CARIBBEAN SEA. WHILE SCATTERED SHOWERS AND
TSTMS ARE OCCURRING N OF 15N WITHIN 300 NM EITHER SIDE OF THE
WAVE AXIS...AN UPPER LEVEL LOW CENTERED NEAR 20N78W CONTINUES TO
PROVIDE SOUTHWESTERLY DIFFLUENT FLOW WEST OF THE WAVE WHICH IS
ENHANCING THE CONVECTION THIS AFTERNOON. LOW-LEVEL MOISTURE
LINGERS FARTHER TO THE EAST ACROSS THE NE CARIBBEAN WITH
ISOLATED SHOWERS AND TSTMS OCCURRING N OF 14N E OF 68W...
INCLUDING PUERTO RICO...THE US/UK VIRGIN ISLANDS...AND THE
LEEWARD ISLANDS. ELSEWHERE...THE MONSOON TROUGH AXIS EXTENDS
FROM THE EAST PACIFIC REGION ALONG 10N TO A 1007 MB LOW CENTERED
NEAR 09N77W. AN UPPER LEVEL DIFFLUENT ENVIRONMENT EXISTS ALOFT
DUE TO AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 07N78W.
SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING S OF 12N
BETWEEN 78W-85W...INCLUDING INLAND PORTIONS OF PANAMA AND COSTA
RICA.

ATLANTIC OCEAN...
A BROAD UPPER LEVEL LOW IS CENTERED IN THE NW CARIBBEAN SEA NEAR
20N78W AND CONTINUES TO DRAW LOW TO MID-LEVEL MOISTURE WESTWARD
AND GENERATE WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS
THE TURKS AND CAICOS ISLANDS...AND SE BAHAMAS S OF 24N BETWEEN
68W-74W. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC N OF
25N...THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF A
ELONGATED E-NE TO W SURFACE RIDGE ANCHORED BY A 1027 MB HIGH
CENTERED NEAR 32N46W. FINALLY OF NOTE...EXAMINING GOES-R PROVING
GROUND DUST IMAGERY...A LARGE PORTION OF THE CENTRAL AND EASTERN
ATLC HAS SUSPENDED SAHARAN DUST N OF 13N E OF A LINE FROM 32N29W
TO 18N47W AND FROM 16N-30N BETWEEN 47W-72W.

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

$$
HUFFMAN




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