[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271048
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN JUL 27 2008

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...

TROPICAL WAVE IS ALONG 32W/33W S OF 20N MOVING W 15 KT. THIS
LARGE WAVE HAS AN ENVELOPE OF LOW-LEVEL CYCLONIC TURNING THAT
COVERS WELL OVER A 10 DEG AREA OF LONGITUDE. THIS CYCLONIC
TURNING IS FOCUSED...VORTICITY MAX...ALONG THE AXIS NEAR 12N.
DESPITE THE HIGH AMPLIFICATION...DEEP CONVECTION IS NEARLY
ABSENT.

TROPICAL WAVE IS TITLED ALONG 28N46W 8N49W MOVING W 10-15 KT. A
WEAK 1014 MB LOW...CONSISTING OF ONLY A THIN SWIRL OF LOW
CLOUDS...IS ALONG THE AXIS NEAR 19N49W. A DISORGANIZED AREA OF
SCATTERED MODERATE CONVECTION IS LOCATED WELL N OF THE SFC LOW
FROM 22N-24N BETWEEN 46W-47W AND THIS IS BEING DRIVEN EVEN
FARTHER AWAY BY SLY WINDS ALOFT. MODEL GUIDANCE SUGGESTS THAT
THIS WAVE WILL SPLIT SOMETIME TODAY AND THE N BRANCH...WHICH
EXHIBITS SOME MID-LEVEL TURNING...WILL LIKELY BE THE MORE ACTIVE
PORTION.

TROPICAL WAVE IS ALONG 78W S OF 19N MOVING W NEAR 20 KT. WHILE
LITTLE SIGNATURE IS APPARENT ON SATELLITE IMAGERY...THE MIMIC
TPW PRODUCT SHOWS A WEAK QUICK MOVING MOISTURE SURGE ASSOCIATED
WITH THIS FEATURE. THE INTERACTION WITH AN UPPER JET IS
PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS OVER
HISPANIOLA...THE WINDWARD PASSAGE AND CUBA.

 ...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N16W 13N28W 10N34W 5N42W 6N54W.
SCATTERED MODERATE CONVECTION IS FROM 5N-10N E OF 16W AND WITHIN
180 NM OF THE AXIS BETWEEN 34W-42W.

...DISCUSSION...

GULF OF MEXICO...
STRONG NE TO E MID TO UPPER FLOW...ON THE PERIPHERY OF A RIDGE
CENTERED OVER W TEXAS AND NEW MEXICO...LIES N OF 24N. THIS FLOW
IS ADVECTING A FAIR AMOUNT OF HIGH CLOUDINESS...SOME OF WHICH IS
BEING DEEPENED TO SCATTERED TSTMS IN WEAK LOW-LEVEL CONFLUENT
AND UPPER DIFFLUENT ZONES NEAR S LOUISIANA N OF 28N BETWEEN
90W-93W AND NEAR THE W COAST OF FLORIDA FROM 25N-29N E OF 87W.
WEAK UPPER TROUGHING LIES OVER THE BAY OF CAMPECHE DRAWING SOME
MOISTURE ON ITS E SIDE OVER THE FAR E PART OF THE BAY AND OVER
THE YUCATAN PENINSULA. AT THE SFC...WEAK 1018 MB HIGH CENTERED
NEAR 27N91W IS ALLOWING WINDS TO BE LIGHT AND ANTICYCLONIC
ACROSS MUCH OF THE AREA. THIS WEAK PRES PATTERN IS EXPECTED TO
HOLD FOR THE NEXT DAY OR TWO.

CARIBBEAN SEA...
SCATTERED SHOWERS AND ISOLATED TSTMS ARE AFFECTING MUCH OF
HISPANIOLA...THE WINDWARD PASSAGE AND CUBA ASSOCIATED WITH A
NARROW NELY UPPER JET SET UP BETWEEN AN UPPER HIGH OVER HONDURAS
AND AN UPPER LOW OVER THE ATLC WATERS NEAR 27N64W. A SMALLER
UPPER LOW IS LOCATED NEAR THE SRN WINDWARDS DRAWING MID-HIGH
LEVEL CLOUDINESS ACROSS THE ANTILLES S OF 14N AND DEEPER SHOWER
ACTIVITY A COUPLE HUNDRED NM E OF TRINIDAD. ELSEWHERE...WATER
VAPOR IMAGES SHOW WIDESPREAD DRY AIR WHICH IS SUPPRESSING THE
DEVELOPMENT OF ANY DEEP TSTM ACTIVITY...WITH EXCEPTION TO THE
ITCZ CONVECTION WHICH SKIRTS THE SW WATERS S OF 10N. TRADE WINDS
REMAIN STRONG OVER THE S CENTRAL WATERS BUT OTHERWISE WINDS ARE
LIGHT TO MODERATE...ESPECIALLY LIGHT OVER THE NW CARIB.

ATLANTIC OCEAN...
A LARGE UPPER LOW CENTERED NEAR 27N64W WITH ASSOCIATED TROUGHING
EXTENDING SW ACROSS CUBA IS PRODUCING DISORGANIZED SCATTERED
SHOWERS AND TSTMS W OF 62W. MID-UPPER RIDGING IS THE GENERAL
THEME ACROSS THE REMAINDER OF THE ATLC ZONE WITH ONE HIGH CENTER
NEAR 21N28W AND A SMALLER ONE NEAR 21N54W. S TO SE UPPER FLOW ON
THE PERIPHERY OF THE RIDGE IS PRODUCING UNFAVORABLE CONDITIONS
FOR THE TROPICAL WAVE APPROACHING 50W. BESIDES FOR AN AREA OF
CONVECTION ASSOCIATED WITH THAT WAVE...MUCH OF THE ATLC IS
DEVOID OF DEEP CLOUDINESS. AT THE SFC...THE ONLY STRONG AREAS OF
WIND NOTED IN RECENT SCATTEROMETER DATA IS NEAR THE TROPICAL
WAVES...DUE TO THE TIGHTENED PRES PATTERN BETWEEN THOSE LOW PRES
FEATURES AND A 1027 MB BERMUDA-AZORES HIGH.

$$
CANGIALOSI


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