Mean: 80.5 /61.2 Median: 81 /61 Range: 93-66 /72-46 Mean: 0.10” % time: 0.10” 0-0.67” 47% VERIFICATIONS: - 72 (74) - Rain – Yes - Cloud: 9.5/10

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Nighttime infrared satellite imagery suggests that the circulation associated with the low pressure area in the Gulf of Mexico is gradually becoming better defined. However, the system is struggling to maintain organized convection near the center, and the radius of maximum winds remains large. Based on this, the system is still maintained as a potential tropical cyclone.

The low is moving erratically northwestward around the southwestern portion of a deep-layer ridge located over the western Atlantic and Florida. The large-scale models suggest this ridge will strengthen some during the next 36 hours or so and cause the low to turn a little more westward. This would be followed by a northward turn around the western end of the ridge and eventual recurvature into the westerlies. Overall, there has been a left shift of the track guidance models since the previous advisory. The new forecast track is also shifted left, but it is to the right of the model consensus, especially at 36-48 h. Given the nature of the circulation, though, and the fact that the wind and rain hazards extend well north and east of the center, users are encouraged to not focus on the details of the track forecast.

The initial intensity remains 35 kt based on partial scatterometer overpasses and continuity from the previous advisory. Significant strengthening is unlikely due to strong vertical shear caused by an upper-level trough over the northwestern Gulf of Mexico and entrainment of dry air into the system. However, the large-scale models suggest slight strengthening before landfall, and thus the intensity forecast is unchanged from the previous advisory. One change from the previous advisory is that it now appears more likely that the system would become a subtropical cyclone rather than a tropical cyclone due to the current structure of the low and interaction with the aforementioned trough. That being said, development into a tropical cyclone remains possible. The primary hazard from this disturbance is expected to be heavy rainfall over portions of the central and eastern Gulf Coast.

FORECAST POSITIONS AND MAX WINDS INIT 20/0900Z 24.8N 90.1W 35 KT 40 MPH...POTENTIAL TROP CYCLONE 12H 20/1800Z 25.7N 91.0W 35 KT 40 MPH...SUBTROPICAL CYCLONE 24H 21/0600Z 26.6N 92.1W 40 KT 45 MPH 36H 21/1800Z 27.5N 93.0W 40 KT 45 MPH 48H 22/0600Z 28.9N 93.5W 40 KT 45 MPH 72H 23/0600Z 32.5N 93.5W 25 KT 30 MPH...INLAND 96H 24/0600Z 36.5N 88.0W 20 KT 25 MPH...POST- TROP/INLAND

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NAM MODEL – 4 panel map Valid at 8 a.m. (12z) YESTERDAY

L H H NAM MODEL – 500 mb. map Valid 8 a.m. (12z) YESTERDAY Ridge Trough

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LIFTED INDEX Valid 2 P.M. (18z) YESTERDAY

5 a.m. (09z)

NAM MODEL – 4 panel map Valid at 2 p.m. (18z)

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LIFTED INDEX Valid 2 P.M. (18z) TODAY

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NAM MODEL – Precip. map Totals (2 pm – 8 pm) (18z – 00z) GFS MODEL – Precip. map Totals (2 pm – 8 pm) (18z – 00z)

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