Tropical Storm Flossie Winds: 55 kt
Pressure: 994 mbar
Advisory 16 / 8:00 AM PDT Thursday, August 1, 2019

Over the last six hours, Flossie has developed a small area of deep convection at the forefront of the remains of its former central dense overcast that has allowed showers to recenter themselves closer to the low-level center of circulation this morning. The combination of shortwave infrared imagery and a microwave pass from SSMI at 1147z both indicate organization has increased since the mess last evening. The suite of both automated and subjective satellite intensity estimates have maintained T3.5/55kt current intensities. Given this, and improvements since the previous advisory, I have raised the advisory intensity to 55 kt.

Now that Flossie has mostly passed west of the Erick-induced PV streamer, deep-layer wind shear magnitudes are expected to slightly decline but remain in the 10-20 kt range over the next two days. The poorly timed decrease in marine instability during this time is expected to keep the environment characteristically marginal despite the somewhat relaxed upper-level flow regime. Some slight intensification could occur within the next two days within these conditions, but likely nothing as significant as we were seeing from some of the guidance two days ago. Shear is expected to rapidly increase at the end of the forecast from the subtropical jet, weakening the system further within hostile parameters near Hawaii.

Nothing new to discuss regarding the track as there is but one steering feature over the next 3-4 days: the subtropical ridge. Models remain tightly clustered in depicting a west-northwesterly track until then. Afterwards, a strong deep-layer trough is expected to enter the region north of Hawaii, potentially curving it northwards at around day 5. Ensemble solutions most favor this possibility, and it is likely that Flossie will be rather weak by then.


INIT 01/1200Z 55 KT 65 MPH

12H 02/0000Z 55 KT 65 MPH

24H 02/1200Z 60 KT 65 MPH

36H 03/0000Z 65 KT 70 MPH

48H 03/1200Z 60 KT 75 MPH

72H 04/1200Z 55 KT 60 MPH

96H 05/1200Z 35 KT 40 MPH

120H 06/1200Z 30 KT 35 MPH

Forecaster TheAustinMan
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