000 WTPZ41 KNHC 290251 TCDEP1 Tropical Storm Erick Discussion Number 7 NWS National Hurricane Center Miami FL EP062019 500 PM HST Sun Jul 28 2019 There have been some significant changes with Erick during the past several hours. First, as foreshadowed in the previous advisory, microwave and scatterometer data indicate that the center has re-formed under a very strong convective cluster farther to the south. Second, the overall cloud pattern has become much better organized, with a CDO-like feature forming near the center and a notable increase in curved banding in the southern and western quadrants of the storm. Erick appears to be in the beginning stages of rapid intensification, and the intensity will be increased to 55 kt for this advisory based on a consensus of estimates from TAFB, SAB and the CIMSS ADT. This is one of these rare forecasts where it is difficult to find a reason not to predict rapid intensification. Erick is expected to be in an environment of very low vertical wind shear and warm water during the next 48 hours. While earlier forecasts were concerned about mid-level dry air, the southward reformation will probably help insulate the storm from that influence, along with the very low shear limiting mixing. Although there is no low-level ring present yet in the latest 37 gHz microwave channel, this signal can be both before and/or concurrent with rapid strengthening. Notably, the SHIPS-rapid intensification index is showing about a 70 percent chance of both a 30-kt increase during the next 24 hours and a 55-kt rise in 48 hours. It's pretty hard to ignore the signal from that model, considering these are values you might see a few times a year. In addition, dynamical models have also come up sharply from the previous cycle, and three typically reliable models now show Erick becoming a major hurricane. Thus, the new NHC intensity forecast is considerably higher than the previous one through 48 hours, at the upper-end of the guidance envelope, and just a little above the corrected-consensus models. The forecast after that time required little adjustment, as a combination of higher shear and dry air aloft should contribute to steady weakening by the end of the forecast period. After accounting for the center re-formation, the initial motion estimate is 270/14 kt. A gradual turn to the west-northwest is forecast during the next couple of days as a ridge weakens to the north, then a turn back to the west is anticipated due to Erick weakening and the ridge slightly strengthening. Model guidance remains in very good agreement this evening, with no significant outlier solutions. While the new track forecast has been shifted southwest of the previous one, it is mostly due to the center re-formation, and the forecast continues to be close to the eastern Pacific model consensus TVCE. FORECAST POSITIONS AND MAX WINDS INIT 29/0300Z 11.7N 133.1W 55 KT 65 MPH 12H 29/1200Z 11.9N 135.3W 65 KT 75 MPH 24H 30/0000Z 12.5N 138.2W 80 KT 90 MPH 36H 30/1200Z 13.2N 141.0W 90 KT 105 MPH 48H 31/0000Z 13.9N 143.6W 100 KT 115 MPH 72H 01/0000Z 15.1N 147.9W 85 KT 100 MPH 96H 02/0000Z 16.0N 152.5W 55 KT 65 MPH 120H 03/0000Z 16.5N 157.3W 40 KT 45 MPH $$ Forecaster Blake