363  
WTPZ44 KNHC 071458  
TCDEP4  
 
TROPICAL STORM IVO DISCUSSION NUMBER 4  
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025  
900 AM CST THU AUG 07 2025  
 
FINDING THE EXACT CENTER OF IVO IS TRICKY THIS MORNING, BUT MY BEST  
GUESS IS THAT ITS TRACK HAS DEVIATED RIGHTWARD SINCE THE PRIOR  
ADVISORY. A PAIR OF HELPFUL MICROWAVE PASSES, AN AMSR2 PASS AT 0850  
UTC AND A SSMIS PASS AT 1050 UTC, SHOWED WELL-DEFINED CURVED BANDING  
ON THE 37-GHZ TO 91-GHZ CHANNELS RESPECTIVELY. MORE RECENTLY, A  
VISIBLE SATELLITE ANIMATION OF 1-MIN GOES-19 IMAGERY SHOWS BURSTING  
CONVECTION NEAR THE ESTIMATED CENTER. SUBJECTIVE DVORAK ESTIMATES BY  
TAFB AND SAB WERE T3.0/45 KT AND T2.5/35 KT RESPECTIVELY, WITH THE  
OBJECTIVE INTENSITY ESTIMATES RANGING FROM 34 TO 51 KT. THUS, THE  
INITIAL INTENSITY HAS BEEN BUMPED UP TO 40 KT THIS MORNING.  
 
IVO APPEARS TO BE MAINTAINING A BRISK WEST-NORTHWESTWARD MOTION,  
ESTIMATED AT 300/21 KT. THIS RAPID FORWARD MOTION IS THANKS IN PART  
TO A STRONG AND LARGE MID-LEVEL RIDGE STRETCHING ACROSS NORTHERN  
MEXICO AND SOUTHWESTERN UNITED STATES. THIS RIDGE IS FORECAST TO  
MOVE ALONG WITH IVO THOUGH IT DOES GRADUALLY DAMPEN OUT IN  
MAGNITUDE. THE NET RESULT OF THIS PATTERN SHOULD KEEP IVO ON A  
GENERAL WEST-NORTHWESTWARD HEADING, WITH THE CYCLONE TURNING MORE  
WESTWARD AND SLOWING DOWN TOWARDS THE LATTER HALF OF THE FORECAST.  
THE TRACK GUIDANCE THIS CYCLE IS A LITTLE FARTHER NORTH, LARGELY A  
REFLECTION OF THE FARTHER NORTH INITIAL POSITION. THE LATEST NHC  
TRACK FORECAST IS ALSO FARTHER NORTH ROUGHLY BLENDING THE SIMPLE AND  
CORRECTED CONSENSUS AIDS (TVCE AND HCCA), BUT STILL REMAINS OFFSHORE  
OF MEXICO, MAKING ITS POINT OF CLOSEST APPROACH IN THE NEXT 12-18  
HOURS.  
 
THE SMALL CORE OF IVO LIKELY COULD MAKE IT SUSCEPTIBLE TO RAPID  
CHANGES IN INTENSITY, EITHER UP OR DOWN. BECAUSE VERTICAL WIND  
SHEAR IS RELATIVELY LOW (10-15 KT), AND SEA SURFACE TEMPERATURES  
REMAIN ABOVE 27 C FOR THE NEXT 36 HOURS, THE NHC INTENSITY FORECAST  
CONTINUES TO SHOW SIGNIFICANT INTENSIFICATION, MAKING IVO A  
HURRICANE. THEREAFTER, THE STORM WILL REACH A SHARP SEA-SURFACE  
TEMPERATURE GRADIENT, AND SHOULD BEGIN A GRADUAL WEAKENING TREND.  
TOWARDS THE END OF THE FORECAST IVO WILL LIKELY LOSE ITS REMAINING  
DEEP CONVECTION OVER THE SUB 24 C WATERS WEST OF BAJA CALIFORNIA,  
MARKING ITS TRANSITION TO A POST-TROPICAL REMNANT LOW BY 96 H. THE  
NHC INTENSITY FORECAST REMAINS A BIT ON THE HIGH END OF THE OVERALL  
MODEL SUITE.  
 
GIVEN THE SMALL RADIUS OF TROPICAL-STORM-FORCE WINDS ASSOCIATED WITH  
IVO, THESE WINDS ARE EXPECTED TO REMAIN OFFSHORE AS IT MAKES ITS  
CLOSEST APPROACH TO MEXICO LATER TODAY. HOWEVER, HEAVY RAIN AND  
ROUGH SURF ARE LIKELY TO OCCUR ALONG PORTIONS OF THE SOUTHWEST COAST  
OF MEXICO DURING THE NEXT DAY OR SO. OUTER BANDS OF IVO ARE  
EXPECTED TO PRODUCE LOCALLY HEAVY RAINFALL IN PORTIONS OF THE  
MEXICAN STATES OF GUERRERO, MICHOACAN DE OCAMPO AND COLIMA THROUGH  
FRIDAY WHERE FLASH FLOODING IS POSSIBLE.  
 
 
FORECAST POSITIONS AND MAX WINDS  
 
INIT 07/1500Z 17.8N 104.4W 40 KT 45 MPH  
12H 08/0000Z 19.5N 106.8W 50 KT 60 MPH  
24H 08/1200Z 20.8N 109.6W 60 KT 70 MPH  
36H 09/0000Z 21.5N 111.7W 65 KT 75 MPH  
48H 09/1200Z 21.7N 113.5W 60 KT 70 MPH  
60H 10/0000Z 21.8N 114.8W 45 KT 50 MPH  
72H 10/1200Z 22.0N 116.3W 35 KT 40 MPH  
96H 11/1200Z 22.5N 119.6W 30 KT 35 MPH...POST-TROP/REMNT LOW  
120H 12/1200Z...DISSIPATED  
 

 
FORECASTER PAPIN  
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab TPC Page Main Text Page