[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 061802
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI OCT 06 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
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...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...SPECIAL FEATURE...
SATELLITE IMAGERY INDICATES THAT A LOW PRESSURE AREA HAS FORMED
ABOUT 310 NM WEST-SOUTHWEST OF BERMUDA.  WHILE THE ASSOCIATED
SHOWER AND THUNDERSTORM ACTIVITY IS CURRENTLY POORLY
ORGANIZED...THERE IS SOME POTENTIAL FOR THE SYSTEM TO DEVELOP
INTO A SUBTROPICAL CYCLONE DURING THE NEXT DAY OR SO AS IT MOVES
NORTHEASTWARD ABOUT 9 KT.  AN AIR FORCE RESERVE HURRICANE HUNTER
IS SCHEDULED TO INVESTIGATE THE SYSTEM ON SATURDAY...IF
NECESSARY. NUMEROUS MODERATE CONVECTION IS EXTENDING NE FROM THE
TURKS AND CAICOS ISLANDS TO NEAR BERMUDA FROM 21N-33N BETWEEN
64W-72W.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 30W/31W S OF 16N MOVING W NEAR 15 KT.
BROAD CYCLONIC TURNING OF THE LOW TO MID CLOUD FIELD NOTED ON
SATELLITE IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 4N-11N
BETWEEN 25W-36W...MOSTLY EMBEDDED WITHIN THE ITCZ. ISOLATED
SHOWERS/TSTMS NOTED ELSEWHERE WITHIN 150NM OF THE AXIS.

TROPICAL WAVE IS ALONG 51W S OF 15N MOVING W 10-15 KT. THIS WAVE
HAS BECOME DIFFICULT TO LOCATE OVER THE PAST COUPLE OF DAYS WITH
UPPER WESTERLY FLOW SOUTH OF AN UPPER TROUGH MASKING THE SIGNAL
A BIT. CONVECTION IS OVERALL MINIMAL WITH ISOLATED SHOWERS/TSTMS
FROM 10N-14N BETWEEN 52W-58W.

LOW AMPLITUDE EASTERN CARIBBEAN TROPICAL WAVE IS ALONG 62W S OF
15N MOVING W 10-15 KT. THIS WAVE IS ALSO DIFFICULT TO LOCATE
THOUGH THE BARBADOS SOUNDING DID SHOW SOME PERTURBATION IN THE
WIND FIELD YESTERDAY. CONVECTION OVERALL MINIMAL WITH A SMALL
PATCH OF MODERATE CONVECTION FROM 12N-14N BETWEEN 61W-63W.

TROPICAL WAVE IS ALONG 84W S OF 21N MOVING W 10-15 KT. AN
INVERTED V PATTERN IS NOTED ON SATELLITE IMAGERY THOUGH THE WAVE
MAY BE TILTED A BIT TO THE NW INTO THE THE SRN GULF OF MEXICO
WITH THE TURNING NOTED N OF THE YUCATAN. THERE IS WIDESPREAD
MODERATE WITH ISOLATED STRONG CONVECTION OFF THE CENTRAL
AMERICAN COAST FROM 10N-20N BETWEEN 80W-88W.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N16W 10N28W 7N36W 9N49W 10N61W.
OUTSIDE OF THE CONVECTION MENTIONED WITH THE TROPICAL
WAVES...SCATTERED MODERATE CONVECTION IS FROM 6N-9N BETWEEN
44W-50W. ISOLATED SHOWERS NOTED ELSEWHERE WITHIN 100NM OF THE
AXIS.

...DISCUSSION...
GULF OF MEXICO...
THE UPPER TROUGH THAT HAS BEEN HUGGING COASTAL TX AND MEXICO THE
LAST FEW DAYS APPEARS TO HAVE WEAKENED AND DRIFTED SW OVER
CENTRAL MEXICO. AN UPPER HIGH IS EXTENDING NW FROM THE YUCATAN.
UPPER DIFFLUENCE BETWEEN THESE FEATURES IS HELPING SUPPORT THE
SCATTERED MODERATE CONVECTION IN THE BAY OF CAMPECHE FROM
18N-23N BETWEEN 92W-98W...ALSO ASSOCIATED WITH THE SURFACE
TROUGH IN THE REGION ALONG 18N94W 24N96W. CONDITIONS IN THIS
REGION ARE NOT FAVORABLE FOR TROPICAL CYCLONE FORMATION.
HOWEVER...LOCALLY HEAVY RAINFALL IS POSSIBLE OVER COASTAL AREAS
OF EASTERN MEXICO OVER THE NEXT DAY OR SO AS THE SYSTEM DRIFTS
SLOWLY WESTWARD. DRY MID TO UPPER AIR IS BEING ADVECTED S INTO
THE NRN GULF AROUND AN UPPER HIGH NEAR ABILENE TEXAS...AND THE
SHARP UPPER TROUGHING OVER THE EASTERN UNITED STATES. THE
ASSOCIATED SURFACE COLD FRONT IS MOVING INTO THE AREA NEAR
HOUSTON TEXAS THROUGH THE GULF WATERS JUST S OF WRN LOUISIANA.
SMALL PATCHES OF SCATTERED MODERATE CONVECTION SEEN IN THE SE
GULF FROM 23N-26N BETWEEN 84W-88W THAT MAY BE ASSOCIATED WITH
THE NRN PORTION OF THE TROPICAL WAVE MOVING THROUGH THE NW
CARIBBEAN. NE TO E WINDS 10-20KT ACROSS THE GULF WILL PERSIST
THE NEXT COUPLE OF DAYS WITH HIGH PRESSURE N OF THE AREA.

CARIBBEAN SEA...
THE CARIBBEAN IS DOMINATED BY MAINLY UPPER WESTERLY FLOW WITH A
A RIDGE/TROUGH/RIDGE PATTERN DOMINATING THE BASIN. A BROAD RIDGE
COVERS MOST OF THE WEST-CENTRAL CARIBBEAN. A WEAK UPPER TROUGH
EXTENDS FROM HISPANIOLA TO NW VENZUELA. THE E CARIBBEAN IS
UNDER THE INFLUENCE OF ANOTHER UPPER LEVEL RIDGE. MINIMAL
CONVECTION NOTED IN THE CARIBBEAN OUTSIDE OF THE TROPICAL WAVE
REGIONS. LOW PRESSURE NEAR THE COLOMBIAN COAST AND ATLANTIC
RIDGE NEAR 30N WILL MAINTAIN MODERATE ELY TRADE WINDS ACROSS THE
CARIBBEAN TONIGHT THROUGH SUNDAY.

ATLANTIC OCEAN...
SHORTWAVE UPPER RIDGE EXTENDING NE FROM N FLORIDA INTO THE
ADJACENT ATLC WATERS IS COLLAPSING WITH SHARP UPPER TROUGHING
MOVING OVER THE EASTERN THIRD OF THE UNITED STATES. THESE
FEATURES CONTINUE TO ADVECT DRY MID TO UPPER AIR S/SE. A SURFACE
TROUGH EXTENDS NNE FROM THE TURKS AND CAICOS ISLANDS TO THE
SPECIAL FEATURE NEAR 30N70W. UPPER S/SW FLOW BETWEEN THE
TROUGHING OVER THE EAST COAST AND AN UPPER HIGH NEAR 28N55W IS
SPREADING THE ASSOCIATED MOISTURE/CLOUD TOPS TO THE N/NE. AN
ELONGATED UPPER TROUGH AXIS IS ALONG 27N33W 19N47W 22N60W WITH A
COUPLE EMBEDDED UPPER LOW CENTERS. UPPER W/SW FLOW S OF THIS
UPPER TROUGHING IS PRODUCING SHEAR OVER THE TROPICAL WAVES IN
THE VICINITY. THE SAME W/SW UPPER FLOW IS SPREADING ABUNDANT
UPPER MOISTURE/HIGH CLOUDS TO THE NE BETWEEN 14N50W AND 25N25W.
A SURFACE TROUGH IS REFLECTING DOWN FROM THE UPPER FEATURES
ALONG 21N33W 30N31W. A MID TO UPPER HIGH IS JUST N OF THE CAPE
VERDE ISLANDS NEAR 19N23W. THE CENTRAL AND ERN ATLC ALSO
DOMINATED BY A PAIR OF 1027 MB SURFACE HIGH PRESSURE CENTERS
NEAR 31N47W AND 36N17W.

$$
WILLIS




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