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Tropical Depression EIGHT-E (Text)

ZCZC MIATCDEP3 ALL
TTAA00 KNHC DDHHMM
 
TROPICAL DEPRESSION EIGHT-E DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP082013
200 AM PDT SUN AUG 04 2013
 
THERE HAS BEEN LITTLE CHANGE IN THE OVERALL CONVECTIVE PATTERN SINCE
THE PREVIOUS ADVISORY. MODERATE NORTH TO NORTHEASTERLY WIND SHEAR
IS KEEPING WHAT LIMITED CONVECTION THERE IS DISPLACED TO THE SOUTH
OF THE CENTER...AND A 0542 UTC AMSU OVERPASS REVEALED VERY LITTLE
IN THE WAY OF BANDING FEATURES. SATELLITE INTENSITY ESTIMATES ARE
45 KT FROM UW-CIMSS ADT...35 KT FROM TAFB...AND 30 KT FROM SAB.
GIVEN THE LACK OF ANY SIGNIFICANT CONVECTIVE BANDING FEATURES...THE
INTENSITY IS BEING MAINTAINED AT 30 KT FOR THIS ADVISORY.

THE INITIAL MOTION ESTIMATE IS 270/08 KT BASED PRIMARILY ON
MICROWAVE SATELLITE FIXES. A WESTWARD MOTION IS FORECAST TO
CONTINUE FOR THE NEXT 24 HOURS OR SO...FOLLOWED BY A TURN TO THE
WEST-NORTHWEST. THE NHC MODEL GUIDANCE IS IN REASONABLE AGREEMENT
ON THIS SHORT-TERM TRACK SCENARIO...BUT THEN DIVERGES SIGNIFICANTLY
AFTER THAT DUE TO THE EXPECTED STRENGTH AND VERTICAL DEPTH OF THE
CYCLONE. THE ECMWF IS FORECASTING A MUCH WEAKER SYSTEM THAT MOVES
MORE WESTWARD AND REMAINS EMBEDDED WITHIN THE ITCZ...WHEREAS THE
GFS AND HWRF ARE FORECASTING A STRONGER AND DEEPER STORM THAT MOVES
POLEWARD OUT OF THE ITCZ. GIVEN THE CONDUCIVE ENVIRONMENTAL AND
OCEANIC CONDITIONS AFTER 18-24 HOURS THAT SHOULD ALLOW THE CYCLONE
TO INTENSIFY POSSIBLY TO NEAR HURRICANE STRENGTH...THE OFFICIAL
FORECAST LEANS MORE TOWARD THE GFS...GFS-ENSEMBLE...AND HWRF
SOLUTIONS...AND LIES NEAR BUT SLIGHTLY TO THE RIGHT OF THE
CONSENSUS MODEL TVCE.

THE MODERATE NORTHERLY VERTICAL WIND SHEAR THAT HAS BEEN PLAGUING
THIS SYSTEM FOR THE PAST FEW DAYS IS FORECAST TO WEAKEN TO LESS
THAN 5 KT BY 48 HOURS AS THE CYCLONE MOVES UNDER A RIDGE AXIS THAT
LIES ALONG 130W LONGITUDE. SSTS ARE 28C AND WARMER AND THE MIDDLE
TROPOSPHERE IS FORECAST TO BE MOIST WITH HUMIDITY VALUES IN EXCESS
OF 70 PERCENT. THESE CONDITIONS WOULD FAVOR AT LEAST SOME MODEST
STRENGTHENING OVER THE NEXT 3 DAYS UNTIL THE CYCLONE MOVES OVER
SUB-26C SSTS BY 96 HOURS. THE BULK OF THE RELIABLE INTENSITY
GUIDANCE IS STILL FORECASTING THE DEPRESSION TO BECOME A HURRICANE
BY 48 HOURS...WHICH IS NOT OUT OF THE QUESTION GIVEN THAT THE
CYCLONE IS EXPECTED TO MAINTAIN A MOIST EQUATORIAL INFLOW PATTERN.
THE INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY...AND IS
CLOSE TO BUT SLIGHTLY LOWER THAN THE CONSENSUS MODEL ICON.

FORECAST POSITIONS AND MAX WINDS
 
INIT  04/0900Z 12.8N 125.6W   30 KT  35 MPH
 12H  04/1800Z 12.8N 126.6W   35 KT  40 MPH
 24H  05/0600Z 12.8N 128.0W   40 KT  45 MPH
 36H  05/1800Z 12.9N 129.5W   45 KT  50 MPH
 48H  06/0600Z 13.6N 131.1W   50 KT  60 MPH
 72H  07/0600Z 14.9N 134.4W   60 KT  70 MPH
 96H  08/0600Z 16.1N 138.2W   50 KT  60 MPH
120H  09/0600Z 17.3N 142.0W   40 KT  45 MPH
 
$$
FORECASTER STEWART
 
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