[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271040
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON JUL 27 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 42W S OF 15N MOVING W NEAR 23 KT. THIS
WAVE COINCIDES WITH A BROAD MAXIMUM IN DEEP LAYER MOISTURE BASED
ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. REMAINING
EMBEDDED WITHIN THE ITCZ...A BROAD LOW-LEVEL CYCLONIC TURNING IS
EVIDENT IN THE LOW LEVEL FLOW WITHIN THE 950-800 MB LAYER ALONG
THE WAVE AXIS NEAR 10N. ISOLATED MODERATE CONVECTION IS FROM
8N-13N BETWEEN 37W-43W.

A TROPICAL WAVE IS ALONG 64W S OF 19N MOVING W NEAR 25-30 KT.
THIS WAVE COINCIDES WITH A WELL-DEFINED MAXIMUM IN DEEP LAYER
MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM
CIMSS. INFRARED SATELLITE IMAGERY INDICATES AN INVERTED-V
SIGNATURE IN THE COVERAGE OF LOW LEVEL CLOUDS NEAR THIS WAVE
ACROSS THE ERN CARIBBEAN. ISOLATED MODERATE CONVECTION AND
SCATTERED SHOWERS ARE OCCURRING FROM 10N-15N BETWEEN 61W-67W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 11N16W 10N41W 10N44W 10N62W.
SCATTERED MODERATE CONVECTION IS FROM 9N-13N BETWEEN 18W-24W.

...DISCUSSION...

GULF OF MEXICO...
A SHARP UPPER LEVEL TROUGH IS OVER THE SE CONUS AND NE GULF WITH
AN AXIS EXTENDING FROM SRN GEORGIA THROUGH 25N90W TO 22N95W.
ATMOSPHERIC LIFT IN MOIST SWLY FLOW ALOFT TO THE E OF THE UPPER
LEVEL TROUGH AXIS IS SUPPORTING SCATTERED SHOWERS AND ISOLATED
TSTMS OVER THE SW GULF S OF 22N E OF 92W WITH MORE WIDELY
SCATTERED SHOWER ACTIVITY S OF 26N BETWEEN 85W-92W...INCLUDING
PORTIONS OF THE YUCATAN CHANNEL. ALL OF THIS SHOWER AND TSTM
ACTIVITY IS ALSO BEING SUPPORTED BY LOW LEVEL SPEED CONVERGENCE
IN THE SURFACE WIND FIELD ACROSS THE CENTRAL AND SW GULF. ACROSS
THE NW GULF...SUBSIDENCE IN NLY FLOW ALOFT W OF THE UPPER LEVEL
TROUGH AXIS...AS WELL AS DEEP LAYER DRY AIR...ARE RESULTING IN
OVERALL FAIR WEATHER. HOWEVER...A FEW ISOLATED SHOWERS ARE NOTED
ON DOPPLER RADAR MOSAIC IMAGERY N OF 28N BETWEEN 85W-90W. SELY
SURFACE WINDS ARE FORECAST TO INCREASE OVER THE W GULF LATE
MONDAY...AS A SURFACE RIDGE ACROSS THE NRN GULF MOVES NEWD
DURING THE NEXT FEW DAYS AND SURFACE LOW PRESSURE DEVELOPS OVER
W TEXAS.

CARIBBEAN SEA...
AN UPPER LEVEL RIDGE IS PRESENT OVER THE NW CARIBBEAN...YUCATAN
PENINSULA AND WRN CUBA THAT EXTENDS FROM AN UPPER LEVEL HIGH
CENTERED NEAR 20N86W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH
THIS UPPER LEVEL RIDGE IS SUPPORTING SCATTERED SHOWERS N OF 20N
W OF 85W. THE REMAINDER OF THE CARIBBEAN REMAINS FAIRLY TRANQUIL
UNDER DEEP LAYER DRY AIR AS MODERATE TO STRONG SUBSIDENCE
PREVAILS BETWEEN 68W-86W. HOWEVER...WEAK LOW-LEVEL CONVERGENCE
AND A REGIONAL AREA OF UPPER DIFFLUENCE IS LOCATED BETWEEN WRN
HISPANIOLA AND JAMAICA THAT IS SUPPORTING SCATTERED SHOWERS AND
ISOLATED TSTMS FROM 17N-20N BETWEEN 73W-77W. GLOBAL MODEL
GUIDANCE INDICATES FRESH TO STRONG TRADE WINDS UP TO 25 KT ARE
EXPECTED TO CONTINUE ACROSS THE BASIN S OF A SURFACE RIDGE
LOCATED OVER THE CENTRAL AND W ATLC. THE STRONGEST WINDS AS
USUAL...UP TO 30 KT...ARE FOUND NEAR THE COAST OF COLOMBIA.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS PRESENT OVER THE ERN CONUS AND EXTENDS
INTO THE NE GULF OF MEXICO. ATMOSPHERIC LIFT IN MOIST SWLY FLOW
ALOFT BETWEEN THIS UPPER LEVEL TROUGH AND AN UPPER LEVEL RIDGE
FARTHER TO THE E OVER THE SW NORTH ATLC IS SUPPORTING SCATTERED
SHOWERS AND TSTMS WITHIN 60 NM EITHER SIDE OF A LINE ALONG
25N79W 31N79W TO BEYOND 32N77W. TO THE E...AN UPPER LEVEL LOW IS
CENTERED NEAR 31N60W. ATMOSPHERIC INSTABILITY IN THE VICINITY OF
THIS UPPER LEVEL LOW IS PRODUCING ISOLATED SHOWERS N OF 27N
BETWEEN 53W-60W. ACROSS THE REMAINDER OF THE CENTRAL AND ERN
ATLC...SUBSIDENCE AND ATMOSPHERIC STABILITY PREVAIL ASSOCIATED
WITH A SURFACE RIDGE ANCHORED ON A 1029 MB HIGH CENTERED NEAR
33N49W THAT IS RESULTING IN GENERALLY FAIR WEATHER. HOWEVER...A
SURFACE TROUGH EXTENDS FROM SRN WESTERN SAHARA AND WRN
MAURITANIA TO A 1010 MB LOW NEAR 18N21W IN THE ERN ATLC. NO
SIGNIFICANT PRECIPITATION ACCOMPANIES THIS LOW...HOWEVER NE
WINDS UP TO 20 KT ARE LOCATED N OF THE SURFACE TROUGH FROM
24N-30N E OF 24W.

$$
HUFFMAN





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