je.st
news
Tropical Storm OLAF Forecast Discussion Number 13
2015-10-18 04:39:49| National Hurricane Center (East Pacific)
Issued at 800 PM PDT SAT OCT 17 2015 000 WTPZ44 KNHC 180239 TCDEP4 TROPICAL STORM OLAF DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL EP192015 800 PM PDT SAT OCT 17 2015 After the pause noted in the previous advisory, Olaf has resumed intensification this evening. Well-defined convective bands with cloud tops colder than -80C have formed around the center, and microwave data show a developing 15 n mi wide eye. Satellite intensity estimates have increased to 55 kt from TAFB and SAB, and there is a recent CIMSS AMSU intensity estimate of 52 kt. Based on these data, the initial intensity is increased to 55 kt. The initial motion is 270/8. Olaf is now moving slower as the subtropical ridge to the north weakens in response to the influence of a mid- to upper-level trough near the U. S. west coast. A general west-northwestward motion is expected for the next two days or so as the cyclone moves on the south side of the weakened ridge. After that time, a second mid- to upper-level trough passing north of the Hawaiian Islands is forecast to cause a break in the ridge, allowing Olaf to turn northwestward by 72 hours and northward by 120 hours. There is little overall change in the guidance since the last advisory. Thus, the new forecast track is very similar to the previous track and lies near the center of the track guidance envelope. There is still some light northwesterly shear over Olaf. However, this is forecast to diminish during the next 24 hours, and improving cirrus outflow suggests this may already be occurring. Based on this, warm sea surface temperatures, and a moist environment, continued strengthening is expected during the next 48 hours. After 72 hours, developing southerly shear and dry air entrainment are expected to cause Olaf to weaken. The new intensity forecast is similar to the previous forecast and is in best agreement with the Florida State Superensemble. It should be noted that the small inner core seen in microwave imagery could allow rapid intensification, and the Rapid Intensification Index of the SHIPS model has a 25-30 percent chance of a 30-kt increase in intensity during the next 24 hours. Should this occur, Olaf could get significantly stronger than currently forecast. FORECAST POSITIONS AND MAX WINDS INIT 18/0300Z 9.2N 131.0W 55 KT 65 MPH 12H 18/1200Z 9.4N 132.3W 65 KT 75 MPH 24H 19/0000Z 9.9N 134.1W 80 KT 90 MPH 36H 19/1200Z 10.4N 135.8W 90 KT 105 MPH 48H 20/0000Z 11.2N 137.4W 100 KT 115 MPH 72H 21/0000Z 13.5N 140.5W 100 KT 115 MPH 96H 22/0000Z 15.5N 142.0W 95 KT 110 MPH 120H 23/0000Z 18.0N 142.5W 80 KT 90 MPH $$ Forecaster Beven
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||