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Tropical Storm CRISTINA Forecast Discussion Number 5
2014-06-10 22:44:55| National Hurricane Center (East Pacific)
Issued at 200 PM PDT TUE JUN 10 2014 000 WTPZ43 KNHC 102044 TCDEP3 TROPICAL STORM CRISTINA DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014 200 PM PDT TUE JUN 10 2014 Although inner-core thunderstorm activity has increased at times since the previous advisory, it has been unable to persist as a central dense overcast feature due to entrainment of dry mid-level air. The result is that Cristina looks much better in visible imagery than it does in IR data, and this is mainly due to the cloud pattern being comprised of mostly dissipating cirrus clouds. Having said that, microwave and conventional satellite imagery have been hinting at the formation of a 30 nmi diameter eye-like feature during the past several hours, but the cyclone has thus far been unable to sustain that development trend owing to the aforementioned dry air intrusions. The advisory intensity of 45 kt is based on a blend of satellite intensity estimates of T3.0/45 kt from both TAFB and UW-CIMSS ADT. The initial motion estimate remains 270/04 kt. Cristina is expected to continue moving generally westward and accompanied by a gradual increase in forward speed as the cyclone comes under increasing influence from a strengthening subtropical ridge that extends westward from northern Mexico to west of Baja California. By 48 hours, Cristina is forecast to turn west-northwestward around the southwestern periphery of the ridge, and that motion is expected to continue through Day 5. The NHC track forecast is just an update of the previous advisory track, and lies south and west of the consensus model TVCE due to the GFDL model having a sharp right-of-track bias from the outset of the forecast. Upper-level shear is forecast to decrease to less than 5 kt during the next 72 hours while Cristina remains over SSTs warmer than 28C. This should allow the cyclone to at least gradually strengthen for the next 24 hours or so despite the occasional dry air intrusions that will disrupt the inner core convection and the intensification process. However, if Cristina can somehow manage to close off an eye despite the relatively dry mid-level environment, then rapid strengthening during the next 24 hours or so would likely occur in such a low vertical wind shear regime. By 96 hours and beyond, the combination of much cooler sea-surface temperatures, drier and more stable air, and increasing southwesterly wind shear should produce gradual to possible rapid weakening. The NHC intensity forecast is similar to the previous advisory and follows the consensus intensity models IVCN and ICON. FORECAST POSITIONS AND MAX WINDS INIT 10/2100Z 15.5N 103.2W 45 KT 50 MPH 12H 11/0600Z 15.6N 104.4W 55 KT 65 MPH 24H 11/1800Z 15.8N 105.7W 65 KT 75 MPH 36H 12/0600Z 16.1N 107.1W 70 KT 80 MPH 48H 12/1800Z 16.7N 108.4W 70 KT 80 MPH 72H 13/1800Z 18.1N 111.0W 70 KT 80 MPH 96H 14/1800Z 19.2N 113.2W 55 KT 65 MPH 120H 15/1800Z 20.0N 115.5W 35 KT 40 MPH $$ Forecaster Stewart
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