[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260523
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN JUL 26 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0430 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE HAS BEEN ADDED TO THE 0000 UTC SURFACE ANALYSIS
ALONG 30W S OF 17N MOVING W NEAR 20 KT. THIS WAVE COINCIDES WITH
A DEEP LAYER MOISTURE MAXIMUM OBSERVED ON TOTAL PRECIPITABLE
WATER IMAGERY. SATELLITE IMAGERY AND SATELLITE DERIVED WINDS
ALSO INDICATE LOW/MID-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE
WAVE AXIS. THE WESTWARD PROPAGATION OF THIS WAVE CAN BE SEEN IN
TROPICAL HOVMOLLER DIAGRAMS. NO DEEP CONVECTION IS CURRENTLY
ASSOCIATED WITH THIS WAVE.

A TROPICAL WAVE EXTENDS FROM 16N49W TO 4N45W MOVING W 25-30 KT.
THIS WAVE IS JUST E OF A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN
TOTAL PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY INDICATES
LOW-LEVEL CYCLONIC TURNING NEAR THE WAVE AXIS ALONG 12N. A
CLUSTER OF NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS
EMBEDDED WITHIN THE ITCZ FROM 8N-10N BETWEEN 46W-49W.

TROPICAL WAVE IS ALONG 85W S OF 21N MOVING NEAR W 20 KT. THIS
WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYER MOISTURE AS
OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE
CONVECTION IS FROM 7N-10N BETWEEN 82W-86W...AND FROM 12N-16N
BETWEEN 83W-86W. THIS CONVECTION IS ENHANCED BY UPPER LEVEL
DIFFLUENCE NEAR AN UPPER LEVEL HIGH NEAR 16N88W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 14N17W 11N29W 9N38W 10N50W
10N63W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS JUST
OFF THE COAST OF AFRICA FROM 8N-11N BETWEEN 13W-20W. SCATTERED
MODERATE CONVECTION IS FROM 9N-11N BETWEEN 35W-39W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD SURFACE RIDGE IS ACROSS THE GULF OF MEXICO EXTENDING W
ALONG 25N FROM THE SUBTROPICAL RIDGE IN THE ATLC. AN UPPER LEVEL
TROUGH IS ACROSS THE NW GULF OF MEXICO WITH AXIS ALONG 30N89W TO
CENTRAL MEXICO NEAR 22N100W. UPPER LEVEL DIFFLUENCE BETWEEN THIS
UPPER LEVEL TROUGH AND AN UPPER LEVEL RIDGE OVER THE YUCATAN
PENINSULA CENTERED NEAR 16N88W ALONG WITH MOIST SWLY FLOW ALOFT
ARE SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE SRN
GULF S OF A LINE EXTENDING FROM 30N83W TO 22N98W. ANTI-CYCLONIC
FLOW IS PRESENT AROUND THE SURFACE RIDGE WITH WINDS REACHING 15
KT IN THE W GULF...AND REACHING 20 KT NEAR THE YUCATAN PENINSULA
COAST. EXPECT THE SURFACE RIDGE TO LIFT N BY MID WEEK...AND SE
FLOW WILL INCREASE OVER THE WRN GULF BY TUE AS LOW PRES DEVELOPS
OVER W TEXAS.

CARIBBEAN SEA...
SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE W CARIBBEAN N OF
12N W OF 83W INCLUDING PORTIONS OF NICARAGUA...HONDURAS...AND
WRN CUBA. THIS ACTIVITY IS ENHANCED BY LOW-LEVEL CONVERGENCE
NEAR A TROPICAL WAVE ALONG 85W ALONG WITH UPPER LEVEL DIFFLUENCE
ASSOCIATED WITH AN UPPER LEVEL HIGH NEAR 16N88W. ELSEWHERE
ACROSS THE CENTRAL AND E CARIBBEAN...GENERALLY FAIR WEATHER
PREVAILS UNDER THE PRESENCE OF A DRY SAHARAN AIR LAYER E OF 78W.
HOWEVER...ATMOSPHERIC INSTABILITY IS GENERATING ISOLATED SHOWERS
N OF 18N BETWEEN 65W-81W INCLUDING HISPANIOLA AND PUERTO RICO.
FRESH TO STRONG TRADE WINDS ARE PRESENT ACROSS MUCH OF THE
CARIBBEAN WITH SURFACE WINDS REACHING 30 KT NEAR THE COAST OF
COLUMBIA. EXPECT A TROPICAL WAVE CURRENTLY IN THE ATLC TO
APPROACH THE LESSER ANTILLES MON.

ATLANTIC OCEAN...
ISOLATED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR W ATLC N OF
22N W OF 75W. THIS ACTIVITY IS SUPPORTED BY UPPER LEVEL
DIFFLUENCE BETWEEN A SHORTWAVE UPPER LEVEL TROUGH OVER THE
FLORIDA PENINSULA AND AN UPPER LEVEL HIGH CENTERED NEAR 28N71
ALONG WITH MOIST SWLY FLOW ALOFT. A SURFACE TROUGH IS ANALYZED N
OF THE BAHAMAS FROM 25N73W TO 27N71W. NO SHOWER ACTIVITY IS
CURRENTLY ASSOCIATED WITH THIS TROUGH. A SECOND SURFACE TROUGH
IS ANALYZED IN THE CENTRAL ATLC FROM 18N50W TO 26N47W. THIS
TROUGH IS A FRACTURED OFF PORTION OF THE TROPICAL WAVE THAT
EXTENDS FROM 16N49W TO 4N45W. NO SHOWER ACTIVITY IS ASSOCIATED
WITH THIS SURFACE TROUGH. ELSEWHERE ACROSS THE ATLC...A BROAD
SURFACE RIDGE IS PRESENT ANCHORED BY A 1030 MB HIGH CENTERED
NEAR 34N42W BRINGING GENERALLY FAIR WEATHER ACROSS THE BASIN. AN
UPPER LEVEL HIGH CENTERED NEAR 23N47W IS ENHANCING CONVECTION
ALONG THE ITCZ.

$$
WALTON








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