[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270557
TWDAT

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

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 29W S OF 20N MOVING W 15 KT. THIS WAVE IS
VERY LARGE WITH ITS ENVELOPE OF LOW-LEVEL CYCLONIC TURNING
COVERING WELL OVER A 10 DEG AREA OF LONGITUDE. THE CYCLONIC
TURNING IS FOCUSED (VORTICITY MAX) ALONG THE AXIS NEAR 11N.
DESPITE THE HIGH AMPLIFICATION...DEEP CONVECTION IS NEARLY
ABSENT.

TROPICAL WAVE IS ALONG 48W/49W FROM 12N-27N MOVING W 10-15 KT. A
WEAK 1014 MB LOW...CONSISTING OF ONLY A THIN SWIRL OF LOW
CLOUDS...IS ALONG THE AXIS NEAR 19N. AN AREA OF SCATTERED
MODERATE CONVECTION IS LOCATED WELL N OF THE SFC LOW FROM
24N-26N BETWEEN 43W-46W 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 WILL LIKELY BE THE
MORE ACTIVE PORTION.

TROPICAL WAVE IS ALONG 77W S OF 19N MOVING W NEAR 20 KT. WHILE
THERE IS LITTLE SIGNATURE APPARENT ON SATELLITE IMAGERY...THE
MIMIC TPW PRODUCT SHOWS A WEAK QUICK MOVING MOISTURE SURGE
ASSOCIATED WITH THIS FEATURE. THE INTERACTION WITH AN UPPER LOW
N OF THE AREA IS PRODUCING SCATTERED SHOWERS AND TSTMS OVER
HISPANIOLA...THE WINDWARD PASSAGE AND E CUBA.

 ...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 13N16W 11N27W 8N38W 10N52W 10N62W.
SCATTERED MODERATE CONVECTION IS FROM 5N-10N E OF 15W. ISOLATED
MODERATE CONVECTION IS FROM 4N-10N BETWEEN 32W-40W.

...DISCUSSION...

GULF OF MEXICO...
STRONG NE TO E MID TO UPPER FLOW...ON THE PERIPHERY OF A RIDGE
CENTERED OVER 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 DIFFLUENT ZONES NEAR S
LOUISIANA N OF 29N BETWEEN 89W-92W AND SW FLORIDA FROM 26N-27N E
OF 83W. 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. THIS WEAK PRES PATTERN IS EXPECTED TO HOLD OVER
THE NEXT DAY OR TWO.

CARIBBEAN SEA...
SCATTERED SHOWERS AND TSTMS ARE AFFECTING MUCH OF HISPANIOLA
...THE WINDWARD PASSAGE AND E 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. 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 INTO THE STRAITS OF FLORIDA 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 21N26W AND A SMALLER ONE NEAR
20N54W. 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/PRECIP.

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 FEATURES THE BERMUDA-AZORES
HIGH.

$$
CANGIALOSI




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