[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301048
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU JUL 30 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 33W S OF 25N MOVING W NEAR 15 KT.
SATELLITE IMAGERY AND SATELLITE DERIVED WINDS INDICATE A BROAD
LOW TO MID-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS.
THIS WAVE ALSO EXHIBITS A HIGH AMPLITUDE DEEP LAYER MOISTURE
MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY...WHILE
BEING SURROUNDED BY SAHARAN DUST. SCATTERED MODERATE CONVECTION
REMAINS EMBEDDED WITHIN THE ITCZ AXIS AND IS FROM 8N-13N BETWEEN
30W-40W.

A TROPICAL WAVE IS ALONG 63W S OF 19N MOVING W NEAR 18 KT. THIS
WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN
TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION
HAS INCREASED IN COVERAGE ACROSS THE WINDWARD ISLANDS AND SE
CARIBBEAN OVER THE PAST 6 HOURS AND IS LOCATED FROM 11N-16N
BETWEEN 59W-69W.

A TROPICAL WAVE IS ALONG 92W S OF 21N MOVING W NEAR 20 KT. THIS
WAVE LIES IN A BROAD AREA OF DEEP LAYER MOISTURE OBSERVED IN
TOTAL PRECIPITABLE WATER IMAGERY ACROSS CENTRAL AMERICA AND SRN
MEXICO BECOMING MORE BROAD IN COVERAGE ACROSS THE E PACIFIC
REGION. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 11N-17N
BETWEEN 90W-94W. THIS CONVECTION IS FURTHER ENHANCED BY UPPER
LEVEL RIDGING AND THUS UPPER LEVEL DIFFLUENCE ACROSS NRN
PORTIONS OF CENTRAL AMERICA AND SRN MEXICO.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 13N16W 11N32W 10N35W 9N42W
11N61W. SCATTERED MODERATE CONVECTION IS FROM 8N-13N BETWEEN
17W-21W. ELSEWHERE SCATTERED SHOWERS ARE FROM 7N-13N BETWEEN
21W-42W.

...DISCUSSION...

GULF OF MEXICO...
FAIRLY TRANQUIL WEATHER DOMINATES ACROSS MUCH OF THE GULF OF
MEXICO AS AN UPPER LEVEL ANTICYCLONE IS CENTERED IN THE CENTRAL
GULF NEAR 25N87W. THIS UPPER LEVEL FEATURE ALONG WITH A SURFACE
RIDGE OF HIGH PRESSURE EXTENDING FROM THE W ATLC WATERS ALONG
29N IS PROVIDING MOSTLY CLEAR SKIES AND S-SELY WIND OF 15 TO 20
KT ACROSS THE GULF W OF 88W. HOWEVER...UPPER LEVEL DIFFLUENCE ON
THE ERN PERIPHERY OF THE UPPER LEVEL RIDGE IS GENERATING A FEW
ISOLATED SHOWERS E OF 83W. MOSTLY CONVECTIVE DEBRIS CLOUDINESS
FROM EARLIER ACTIVITY IS ACROSS THE NRN GULF WATERS AND FLORIDA
PENINSULA THIS MORNING. THE OTHER AREA TO NOTE ACROSS THE GULF
IS THE TROPICAL WAVE ALONG 92W THAT IS BRINGING ISOLATED SHOWERS
TO THE S/CENTRAL GULF S OF 22N AND AREAS W TO 93W INCLUDING THE
YUCATAN PENINSULA AND ERN BAY OF CAMPECHE.

CARIBBEAN SEA...
NORTHERLY UPPER LEVEL WINDS PREVAIL ACROSS MUCH OF THE CARIBBEAN
BASIN AS AN UPPER LEVEL RIDGE EXTENDS FROM AN UPPER LEVEL
ANTICYCLONE CENTERED OVER THE ERN GULF OF MEXICO. THE NLY WINDS
ALOFT ARE KEEPING THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE
DRY AND FAIRLY STABLE. HOWEVER...A TROPICAL WAVE ALONG 63W IS
IMPACTING THE FAR ERN CARIBBEAN AND LESSER ANTILLES WITH
SCATTERED SHOWERS AND ISOLATED TSTMS FROM 11N-16N BETWEEN
59W-69W. ACROSS THE WRN CARIBBEAN...THE TROPICAL WAVE ALONG 92W
AND AN UPPER LEVEL DIFFLUENT PATTERN IS GENERATING WIDELY
SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS PORTIONS OF THE GULF
OF HONDURAS AND AREAS OF INTERIOR HONDURAS AND NICARAGUA. S OF
13N...SCATTERED SHOWERS AND TSTMS ARE OCCURRING BETWEEN 75W-84W
DUE TO UPPER LEVEL DIFFLUENCE AND THE PROXIMITY OF THE ITCZ AXIS
ALONG 8N CROSSING OVER PANAMA AND NRN COLOMBIA. FRESH TO STRONG
TRADE WINDS ARE NOTED ACROSS MUCH OF THE CARIBBEAN WITH THE
STRONGEST WINDS NEAR THE COAST OF COLOMBIA.

ATLANTIC OCEAN...
A SHORTWAVE UPPER LEVEL TROUGH LOCATED OFFSHORE ALONG THE MID-
ATLC U.S. SEABOARD IS ENHANCING SCATTERED SHOWERS AND TSTMS OVER
THE SW NORTH ATLC WATERS COVERING THE AREA WITHIN 90 NM EITHER
SIDE OF A LINE FROM 25N79W TO BEYOND 32N75W. ENHANCEMENT OF THIS
CONVECTION IS DUE IN LARGE PART TO UPPER LEVEL DIFFLUENCE
LOCATED ON THE ERN PERIPHERY OF THE UPPER LEVEL ANTICYCLONE
CENTERED OVER THE ERN GULF OF MEXICO. THE REMAINDER OF THE ATLC
IS DOMINATED BY DRY STABLE AIR AND A BROAD SURFACE RIDGE
ANCHORED BY A 1026 MB HIGH NEAR 33N56W BRINGING GENERALLY FAIR
WEATHER ACROSS THE BASIN. ONE EXCEPTION IS AN AREA OF CLOUDINESS
AND POSSIBLE ISOLATED SHOWERS N OF THE TROPICAL WAVE ALONG 33W
FROM 24N-31N BETWEEN 25W-35W. OTHER LOW-LEVEL ISOLATED SHOWERS
ARE POSSIBLE ACROSS THE CENTRAL ATLC BETWEEN 45W-65W ON THE SRN
PERIPHERY OF THE SURFACE RIDGE.

$$
HUFFMAN





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