[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270556
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 40W S OF 16N 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. SCATTERED MODERATE CONVECTION IS FROM
8N-13N BETWEEN 37W-42W.

A TROPICAL WAVE IS ALONG 62W S OF 18N 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.
SCATTERED SHOWERS ARE OCCURRING FROM 10N-16N BETWEEN 60W-66W.

A TROPICAL WAVE IS ALONG 93W S OF 20N MOVING W NEAR 18 KT. THIS
WAVE IS EMBEDDED WITHIN A BROAD MAXIMUM IN DEEP LAYER MOISTURE
BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 14N-19N
BETWEEN 92W-100W. THIS CONVECTION IS BEING ENHANCED BY UPPER
LEVEL DIVERGENCE ASSOCIATED WITH AN UPPER LEVEL RIDGE EXTENDING
FROM THE NW CARIBBEAN WWD OVER SRN MEXICO AND THE ADJACENT
COASTAL WATERS.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 13N17W 10N38W 10N41W 10N60W.
SCATTERED MODERATE CONVECTION IS FROM 9N-13N BETWEEN 18W-23W.

...DISCUSSION...

GULF OF MEXICO...
A SHARP UPPER LEVEL TROUGH IS OVER THE N/CENTRAL AND NE GULF
WITH AN AXIS EXTENDING FROM THE SE CONUS THROUGH 27N90W TO
22N96W. 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 CENTRAL AND SW GULF WITHIN 150 NM EITHER
SIDE OF A LINE FROM 28N85W TO 20N94W. THIS SHOWER AND TSTM
ACTIVITY IS ALSO BEING SUPPORTED BY LOW LEVEL SPEED CONVERGENCE
IN THE SURFACE WIND FIELD ACROSS THE CENTRAL 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 WITH ONLY REMNANT CONVECTIVE DEBRIS HIGH CLOUDS
ACROSS THE NRN GULF. 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/NRN MEXICO.

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 21N
W OF 82W. THE REMAINDER OF THE CARIBBEAN REMAINS FAIRLY TRANQUIL
UNDER DEEP LAYER DRY AIR AS MODERATE TO STRONG SUBSIDENCE
PREVAILS BETWEEN 67W-85W. HOWEVER...WEAK LOW-LEVEL CONVERGENCE
AND A REGIONAL AREA OF UPPER DIFFLUENCE IS LOCATED OVER WRN
HISPANIOLA AND IS SUPPORTING SCATTERED SHOWERS AND ISOLATED
TSTMS FROM 18N-20N BETWEEN 72W-75W. FRESH TO STRONG TRADE WINDS
ARE OCCURRING ACROSS THE BASIN S OF A SURFACE RIDGE OVER THE
CENTRAL AND W ATLC. THE STRONGEST WINDS ARE FOUND NEAR THE COAST
OF COLOMBIA...WHERE NE WINDS OF 25 TO 30 KT ARE OCCURRING.

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 CENTERED NEAR 29N71W IS
SUPPORTING SCATTERED SHOWERS AND TSTMS N OF 25N W OF 78W. TO THE
E...AN UPPER LEVEL LOW IS CENTERED NEAR 30N60W. ATMOSPHERIC
INSTABILITY IN THE VICINITY OF THIS UPPER LEVEL LOW IS PRODUCING
ISOLATED SHOWERS N OF 27N BETWEEN 54W-61W. ACROSS THE REMAINDER
OF THE CENTRAL AND ERN ATLC...SUBSIDENCE AND ATMOSPHERIC
STABILITY PREVAIL ASSOCIATED WITH A SURFACE RIDGE ANCHORED ON A
1030 MB HIGH CENTERED NEAR 34N47W THAT IS RESULTING IN GENERALLY
FAIR WEATHER. HOWEVER...A SURFACE TROUGH EXTENDS FROM WRN
MAURITANIA TO 18N22W IN THE ERN ATLC WITH NE WINDS UP TO 25 KT
FOUND ON AN EARLIER SCATTEROMETER PASS FROM 24N-30N E OF 26W.

$$
HUFFMAN



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