526 
 WTPZ45 KNHC 062035
 TCDEP5
  
 TROPICAL STORM JOVA DISCUSSION NUMBER   4
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP102011
 200 PM PDT THU OCT 06 2011
  
 DEEP CONVECTION HAS PERSISTED NEAR THE CENTER OF THE CYCLONE AND THE
 SHEAR PATTERN APPEARS TO BE STEADILY EVOLVING INTO MORE OF A
 BANDING PATTERN. THE INITIAL INTENSITY OF 35 KT IS BASED ON A BLEND
 OF SATELLITE INTENSITY ESTIMATES OF T2.5/35 KT FROM TAFB AND SAB...
 AND AN ADT ESTIMATE OF T2.6/37 KT FROM UW-CIMSS. THESE ESTIMATES
 ARE FURTHER SUPPORTED BY A 06/1654Z ASCAT OVERPASS THAT INDICATED
 30-KT WINDS EXISTED IN THE SOUTHEAST QUADRANT OUTSIDE OF DEEP
 CONVECTION. AS A RESULT...TD-10E HAS BEEN UPGRADED TO TROPICAL
 STORM JOVA.
  
 THE INITIAL MOTION ESTIMATE IS 310/09 KT...BASED MOSTLY ON MICROWAVE
 SATELLITE FIXES. JOVA IS CURRENTLY LOCATED ABOUT 650 NMI EAST OF
 STRENGTHENING TROPICAL STORM IRWIN. ALTHOUGH IRWIN PRESENTLY HAS
 BETTER BANDING FEATURES...THE TWO CYCLONES ARE COMPARABLE IN SIZE.
 GIVEN THE PROXIMITY TO EACH OTHER...SOME BINARY/FUJIWHARA
 INTERACTION IS LIKELY FOR THE NEXT 2 DAYS OR SO...WHICH SHOULD
 BRING THE TWO CYCLONES CLOSER TO EACH OTHER AND ALSO SLOW DOWN THE
 FORWARD SPEED OF BOTH SYSTEMS. BY 72 HOURS...A BROAD MID-LATITUDE
 TROUGH IS FORECAST TO DROP SLOWLY SOUTHWARD INTO THE SOUTHWESTERN
 U.S. AND NORTHWESTERN MEXICO...WHICH IS EXPECTED TO ERODE THE
 WESTERN PORTION OF A NARROW SUBTROPICAL RIDGE LOCATED TO THE NORTH
 OF JOVA. THE RESULT SHOULD BE FOR JOVA TO GRADUALLY RECURVE TO THE
 NORTHEAST ACCOMPANIED BY A STEADY INCREASE IN FORWARD SPEED. THE
 OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY
 TRACK...AND LIES SOUTH OF THE MODEL CONSENSUS...BUT NOT NEARLY AS
 FAR SOUTH AND AS SLOW AS THE ECMWF MODEL SOLUTION. GIVEN THAT AT
 LEAST HALF OF THE AFOREMENTIONED MID-LATITUDE TROUGH LIES TO THE
 WEST OF AND...THEREFORE...OUTSIDE OF THE NORTH AMERICAN UPPER-AIR
 OBSERVING NETWORK...IT WOULD PRUDENT NOT TO MAKE ANY SIGNIFICANT
 TRACK CHANGES AT THIS TIME.
 
 JOVA IS FORECAST TO REMAIN OVER SSTS GREATER THAN 28C... IN A
 LOW VERTICAL WIND SHEAR REGIME...AND IN A VERY MOIST MID-LEVEL
 ENVIRONMENT WITH HUMIDITY VALUES OF 70-80 PERCENT. THIS WOULD
 USUALLY EQUATES TO A PATTERN CONDUCIVE FOR STEADY OR EVEN RAPID
 STRENGTHENING TO OCCUR. HOWEVER...THE SHIPS AND LGEM MODELS ARE NOT
 REFLECTING ANY SIGNIFICANT INTENSIFICATION AND BARELY MAKE JOVA A
 HURRICANE BY 72 HOURS...WITH STEADY WEAKENING FORECAST AFTER THAT.
 IN CONTRAST...THE HWRF AND GFDL MODELS STEADILY STRENGTHEN JOVA TO
 85 KT AND 100 KT...RESPECTIVELY...BY 96 HOURS. GIVEN THE FAVORABLE
 PARAMETERS MENTIONED PREVIOUSLY...THE OFFICIAL INTENSITY FORECAST
 HAS BEEN INCREASED ABOVE THE SHIPS/LGEM MODELS AND IS SIMILAR TO
 THE HWRF MODEL SOLUTION. ALTHOUGH JOVA IS FORECAST TO BE INLAND
 OVER SOUTHWESTERN MEXICO BY 120 HOURS...TROPICAL STORM INTENSITY IS
 BEING INDICATED AT THAT TIME DUE TO THE OUTER WIND FIELD...WHICH
 COULD STILL CONTAIN TROPICAL-STORM-FORCE WINDS...EXPECTED TO REMAIN
 OFFSHORE AT THAT TIME.
 
 IT IS IMPORTANT NOT TO FOCUS ON THE EXACT TRACK FORECAST AT DAYS 4
 AND 5 SINCE THE AVERAGE TRACK ERRORS IN THE EASTERN PACIFIC BASIN AT
 THAT THOSE TIME PERIODS ARE 175 TO 225 MILES.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  06/2100Z 12.5N 107.5W   35 KT  40 MPH
  12H  07/0600Z 13.4N 108.5W   40 KT  45 MPH
  24H  07/1800Z 14.3N 109.2W   45 KT  50 MPH
  36H  08/0600Z 15.0N 109.6W   55 KT  65 MPH
  48H  08/1800Z 16.2N 109.7W   65 KT  75 MPH
  72H  09/1800Z 18.0N 108.7W   75 KT  85 MPH
  96H  10/1800Z 19.2N 106.7W   85 KT 100 MPH
 120H  11/1800Z 20.5N 104.0W   35 KT  40 MPH...INLAND
  
 $$
 FORECASTER STEWART
  
 
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