[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 292346 CCA
TWDAT

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI JUN 29 2007

CORRECTED SATELLITE IMAGERY TIME

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
SECTIONS OF SOUTH AMERICA...AND THE 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS TITLED ALONG 14N29W 3N32W MOVING W 15-20 KT.
THIS WAVE WAS ADJUSTED AHEAD EARLIER BASED ON ELONGATED CYCLONIC
TURNING SEEN ON VISIBLE IMAGERY. SATELLITE DERIVED WINDS IN THE
600-800 MB RANGE CONFIRM THIS TURNING SHOWING THE PRESENCE OF
THE WAVE AXIS OFF THE SFC. SHOWER ACTIVITY IS MINIMAL AND
EMBEDDED IN THE ITCZ.

TROPICAL WAVE IS ANALYZED IN THE ERN CARIB ALONG 63W/64W MOVING
W 15-20 KT OVER THE PAST 24 HOURS. THIS WAVE IS LESS ORGANIZED
THAN IT WAS OVER THE PAST COUPLE OF DAYS WITH LITTLE STRUCTURE
IN ITS CLOUD FIELD. EVEN IN THE SURROUNDING STABLE UPPER
ENVIRONMENT...THIS WEAK WAVE IS PRODUCING SCATTERED SHOWERS AND
ISOLATED TSTMS S OF 15N WITHIN 150 NM EITHER SIDE OF THE AXIS.

TROPICAL WAVE EXTENDS ACROSS CENTRAL AMERICA INTO THE WRN BAY OF
CAMPECHE ALONG 90W S OF 21N MOVING W 10-15 KT. SCATTERED SHOWERS
AND TSTMS...POSSIBLY ENHANCED BY THIS WAVE...ARE MOVING NWD WITH
THE UPPER FLOW FROM 20N-23N BETWEEN 88W-91W. A WEAK AREA OF LOW
PRES OVER S FLORIDA BROKE OFF FROM THE NRN BRANCH OF THIS WAVE A
FEW DAYS AGO. FOR DETAILS REFER TO THE DISCUSSION SECTION
BELOW.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N15W 10N24W 9N40W 7N50W 10N63W.
SCATTERED MODERATE CONVECTION IS WITHIN 150 NM EITHER SIDE OF
THE AXIS BETWEEN 17W-25W. ISOLATED MODERATE IS WITHIN 60 NM
EITHER SIDE BETWEEN 43W-51W.

...DISCUSSION...
GULF OF MEXICO...
AN UPPER LOW IS SPINNING OVER THE BAY OF CAMPECHE CENTERED NEAR
21N95W. EXTENSIVE SLY UPPER FLOW BETWEEN THIS LOW AND AN UPPER
HIGH CENTERED OVER THE NW CARIB IS DRIVING SOME TROPICAL
MOISTURE NWD ACROSS THE YUCATAN PENINSULA AND MUCH OF THE GULF.
MOST OF THIS MOISTURE PLUME IS IN THE FORM OF MID-HIGH LEVEL
CLOUDS AND ISOLATED SHOWERS...EXCEPT OVER THE YUCATAN COASTAL
WATERS AND WITHIN 90 NM OF THE UPPER LOW CENTER WHERE SCATTERED
SHOWERS AND TSTMS EXIST. IN THE LOWER LEVELS...A WEAK AREA OF
LOW PRES IS LOCATED OVER S FLA AND EXTENDS A TROUGH ALONG 81W N
OF 23N. THIS FEATURE BROKE OFF FROM THE NRN BRANCH OF A TROPICAL
WAVE NOW LOCATED ALONG 90W. MOST OF THE ASSOCIATED DEEP
CLOUDINESS IS LOCATED TO THE E OF THE REGION OVER THE BAHAMAS
SHUNTED BY STRONG MID-UPPER WLY FLOW. WEAK 1018 MB HIGH CENTER
IS LOCATED IN THE MID-GULF NEAR 28N89W PROVIDING LIGHT WINDS.

LOOKING AHEAD INTO THE WEEKEND...NWP MODELS DRIFT THE
BROAD LOW OVER S FLA TO THE NNE INTO THE WRN ATLC AHEAD OF THE
NEXT FRONT. THIS WILL ALLOW WEAK HIGH PRES TO REMAIN IN CONTROL
KEEPING WINDS AND SEAS OF LITTLE CONCERN. THE GREATEST CHANCE OF
SHOWER ACTIVITY IS EXPECTED TO BE IN THE W GULF NEAR THE UPPER
LOW/TROUGH AIDED BY LOW-LEVEL RETURN FLOW.

CARIBBEAN SEA...
A BROAD UPPER RIDGE COVERS MUCH OF THE CARIB ANCHORED BY A HIGH
CENTER NEAR 19N80W. NLY UPPER FLOW E OF THE HIGH IS PROVIDING A
STABLE AIRMASS FOR MUCH OF THE REGION. ONE ELEMENT INHIBITING
FAIR WEATHER IS A TROPICAL WAVE ALONG 63W/64W. THIS FEATURE IS
GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS S OF 15N E OF
68W. SIMILAR ACTIVITY IS OCCURRING IN THE EXTREME SW
CARIB...PANAMA...COSTA RICA AND HONDURAS IN A DIFFLUENT ZONE S
OF THE UPPER HIGH AND NEAR THE ITCZ AXIS. TRADES HAVE RELAXED
SLIGHTLY TODAY WITH THE STRONGEST WINDS NEAR 20 KT ACROSS THE
CENTRAL CARIB. THESE WINDS ARE EXPECTED TO INCREASE A LITTLE AND
EXPAND EWD OVER THE NEXT COUPLE OF DAYS.

ATLANTIC OCEAN...
A LARGE AREA OF SCATTERED SHOWERS AND TSTMS EXTEND ACROSS THE
BAHAMAS AND THE SW ATLC ROUGHLY W OF 70W FROM 23N-30N. THIS
ACTIVITY IS ASSOCIATED WITH A TROUGH OF LOW PRES OVER S FLORIDA
AND UPPER DIFFLUENCE TO THE S OF AN UPPER JET. THIS UPPER JET IS
STRETCHING DEBRIS HIGH LEVEL MOISTURE EWD TO ABOUT 50W N OF 23N.
A PAIR OF WEAK SFC TROUGHS...ALONG 57W FROM 24N-29N AND ALONG
50W FROM 26N-30N...ARE EMBEDDED IN THIS MOISTURE PLUME AIDING IN
THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWER ACTIVITY.
FARTHER E...THE THEME IS EXTENSIVE UPPER RIDGING STRETCHING W
FROM AFRICA ALONG 24N TO ABOUT 30W WITH RIDGING CONTINUING SW
FROM THERE TO ANOTHER UPPER HIGH IN THE TROPICAL N ATLC NEAR
15N45W. DIFFLUENCE AT THE W PERIPHERY OF THE RIDGE...ALONG WITH
LOW-LEVEL INSTABILITY FROM A NEARBY TROPICAL WAVE...IS PRODUCING
SCATTERED SHOWERS AND TSTMS S OF 16N BETWEEN 52W-58W. ELSEWHERE
OUTSIDE OF THE ITCZ REGION...DEEP MOISTURE IS LIMITED UNDER A
SUBSIDENT ENVIRONMENT.

A STRONG SFC RIDGE ALONG 31N/32N CONTINUES TO PROVIDE THE REGION
WITH MODERATE ELY FLOW ACROSS THE SUBTROPICAL/TROPICAL BELT.
SLIGHTLY STRONGER WINDS ARE NEAR THE AFRICAN COAST WHERE THE
PRES GRADIENT TIGHTENS DUE TO INVERTED TROUGHING OVER THE
CONTINENT AND ACROSS THE BAHAMAS WHERE THERE IS SLIGHT
TIGHTENING IN THE GRADIENT DUE TO LOWER PRES OVER FLORIDA.

$$
CANGIALOSI




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