je.st
news
Tropical Storm KARINA Forecast Discussion Number 37
2014-08-22 04:36:43| National Hurricane Center (East Pacific)
Issued at 800 PM PDT THU AUG 21 2014 000 WTPZ41 KNHC 220236 TCDEP1 TROPICAL STORM KARINA DISCUSSION NUMBER 37 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014 800 PM PDT THU AUG 21 2014 Deep convection has continued to develop near the center of Karina, especially in the southern semicircle, and the low-level center is embedded in the middle of the more circular cloud shield. Two earlier ASCAT passes showed 50 kt and 52 kt peak surface winds to the southeast of the center, so the intensity has been bumped up to 55 kt for this advisory. The initial motion estimate is 090/02 kt based on microwave satellite positions over the past several hours. After nearly three days of saying the same thing in our discussions, there isn't much more to add. Karina will gradually get pulled eastward and northeastward by the larger circulation of Tropical Storm Lowell, as the latter cyclone passes to the northeast of Karina in 2-3 days. The majority of the NHC track guidance is now indicating a considerably slower forward speed on Days 4 and 5 as Karina weakens over cold water and becomes more vertically shallow. The official advisory track is similar to but a little faster than the consensus model TVCE out of respect for the faster GFS model. Recent microwave images continue to show a partial eyewall structure. The vertical shear is forecast to subside to around 5 kt during the next 12 hours, so there is a brief window of opportunity for Karina to strengthen. However, the vertical shear is forecast to increase again at 24 hours and beyond as the cyclone begins to move over cooler water. This combination of unfavorable conditions should induce gradual weakening, with the Karina becoming a non-convective remnant low pressure by 96 hours when the cyclone is moving over 22-23C sea-surface temperatures and into a much cooler and drier airmass. The NHC intensity forecast closely follows the intensity consensus model ICON. FORECAST POSITIONS AND MAX WINDS INIT 22/0300Z 14.8N 136.5W 55 KT 65 MPH 12H 22/1200Z 15.1N 135.9W 55 KT 65 MPH 24H 23/0000Z 15.7N 135.1W 50 KT 60 MPH 36H 23/1200Z 16.4N 134.1W 45 KT 50 MPH 48H 24/0000Z 17.3N 132.8W 40 KT 45 MPH 72H 25/0000Z 19.0N 129.8W 35 KT 40 MPH 96H 26/0000Z 21.5N 129.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 27/0000Z 25.5N 130.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Stewart
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics