Central & Eastern Pacific Tropical Cyclone Outlook # 8 for July 29th, 2019

Intermediate Update for Monday Afternoon, Full major update at 23:00 Hours (11pm).

The National Hurricane Center (NHC) and Central Pacific Hurricane Center (CPHC) continues to monitor 2 Tropical Cyclones and one area of interest in the Eastern Pacific & Central Pacific basins:

- Hurricane Erick: currently 1,100 miles ESE of Hilo & moving to the west at 17 mph. With maximum sustained winds of 75 mph (Category 1 Hurricane).

- Tropical Storm Flossie: currently 2,450 miles ESE of Hilo & moving westward at 17 mph. With maximum sustained winds of 65 mph. Flossie is expected to become a hurricane by Tuesday Night.

- Area of Interest in the East Pacific has low chance of formation in the next 5 days, we will continue to monitor this potential disturbance in the coming days.

Based on the latest models reviewed, Hurricane Erick is still expected to past to the south of the Island of Hawaii around Friday morning into Saturday, exactly how far south still remains unknown at this time. Wet Weather Associated with Erick is expected to come onshore Thursday night going into the weekend. Some breezy conditions are also expected as Erick passes to the south as weak Tropical Storm.

Tropical Storm Flossie: it's again still too early to determine the exact track of Flossie and it impacts to Hawaii Island, we will have a better idea of the projected forecast around Friday and Saturday at the earliest as it expected to cross into the Central Pacific basin on Saturday.

Currently, No Watches or Warnings are in effect at this time related to these disturbances.

The next HIRSC Team Update will be made at 23:00 Hours (11:00 pm) Monday Night.

Update on Tropical Storm Erick as of 5:00 pm HST July 29th, 2019:

Hurricane Erick Discussion Number 11...corrected NWS National Hurricane Center Miami FL EP062019 500 PM HST Mon Jul 29 2019 Corrected Central Pacific Hurricane Center web link Erick has finally become a hurricane. Microwave and visible data indicate that a ragged eye is present, and deep convection has been increasing near the center. All of the satellite agencies agree on an initial intensity of 65 kt, so that will be the advisory wind speed. The environment is expected to generally be conducive for continued intensification during the next 36-48 hours, and Erick could still attain major hurricane status during that time. Thereafter, a significant increase in shear is predicted by almost all of the guidance. This is a strong signal for rapid weakening in the 2-3 day time frame, and the official forecast follows suit, showing a more rapid weakening than the previous advisory. The hurricane has been moving faster to the west recently, but a longer-term motion is 280/16. The mid-level ridge to the north is still forecast to weaken tomorrow but stay in place, causing a slower west-northwestward track. Track guidance is more divergent tonight with the ECMWF and its ensemble considerably faster than the rest of the models. It is notable, however, that the models have been doing a rather poor job on the track as they all have been biased too slow and poleward during the past couple of days. Thus, the new forecast has been shifted to the southwest of the previous one, on the western side of the model consensus, but is still behind the ECMWF guidance for forecast continuity. This is the last NHC advisory on Erick since the hurricane is crossing 140W and moving into the central Pacific basin. Future information on this system can be found in Public Advisories issued by the Central Pacific Hurricane Center beginning at 11 PM HST, under AWIPS header HFOTCPCP1, WMO header WTPA31 PHFO, and on the web at http://hurricanes.gov/cphc. FORECAST POSITIONS AND MAX WINDS INIT 30/0300Z 12.7N 140.0W 65 KT 75 MPH 12H 30/1200Z 13.1N 142.2W 75 KT 85 MPH 24H 31/0000Z 13.9N 144.5W 85 KT 100 MPH 36H 31/1200Z 14.6N 146.7W 95 KT 110 MPH 48H 01/0000Z 15.2N 148.8W 95 KT 110 MPH 72H 02/0000Z 16.0N 153.0W 60 KT 70 MPH 96H 03/0000Z 16.7N 157.4W 45 KT 50 MPH 120H 04/0000Z 17.7N 161.4W 35 KT 40 MPH

Tropical Storm Flossie Update as of 5:00pm HST July 29th, 2019:

Tropical Storm Flossie Discussion Number 7 NWS National Hurricane Center Miami FL EP072019 500 PM HST Mon Jul 29 2019 Flossie's satellite appearance in visible, infrared, and microwave channels has steadily improved since the previous advisory, including the development of a small CDO feature. However, nearly identical to Hurricane Erick this time last night, Flossie's low-level center has migrated southward toward the strongest convection and is positioned just north of the coldest cloud tops. Similarly, Flossie is being affected by occasional intrusions of dry air and some northerly mid-level wind shear that is undercutting the otherwise favorable upper-level outflow pattern. The initial intensity of 55 kt is based on a blend of satellite estimates of T3.5/55 kt from TAFB, T3.0/45 kt from SAB, and T3.9/63 kt and 60 kt from UW-CIMMS ADT and SATCON, respectively. The initial motion estimate is westward or 270/15 kt. Despite the recent west-southwestward jog -- deja vu Erick last night -- the models are in excellent agreement that Flossie will move westward for the next 24 hours along the southern periphery of a deep-layer subtropical ridge, followed by a turn toward the west-northwest on Wednesday, with that motion continuing through the remainder of the forecast period. The new official forecast track is south of and slightly faster than the previous advisory track, mainly due to the more southerly initial position, and lies between the tightly clustered consensus models and the more southerly ECMWF model. If not for dry air mid-level occasionally wrapping into the hurricane's inner core, Flossie would be poised to rapidly intensify as per the lastest SHIPS model Rapid Intensification Index (RII). However, similar to Hurricane Erick, the best course of action is to just show steady strengthening until a more persistent RI signal becomes evident. Thus, Flossie is forecast to gradually intensify into a category 3 hurricane by 72 hours, followed by a near-steady state condition thereafter due to Flossie moving across cooler water, which is bounded by the 26C and 26.5C SST isotherms. The official intensity forecast is very similar to the previous advisory, and is close to a blend of the NOAA HCCA and the Florida State Superensemble consensus models. FORECAST POSITIONS AND MAX WINDS INIT 30/0300Z 12.3N 117.8W 55 KT 65 MPH 12H 30/1200Z 12.4N 119.9W 65 KT 75 MPH 24H 31/0000Z 12.8N 122.4W 75 KT 85 MPH 36H 31/1200Z 13.3N 125.0W 85 KT 100 MPH 48H 01/0000Z 14.1N 127.6W 95 KT 110 MPH 72H 02/0000Z 15.9N 133.5W 100 KT 115 MPH 96H 03/0000Z 17.4N 139.2W 100 KT 115 MPH 120H 04/0000Z 18.5N 144.4W 90 KT 105 MPH

Area of Interest (Being Watched by the NHC) Update as of 5:00 pm July 29th, 2019:

Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Jul 29 2019 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0130 UTC. ...SPECIAL FEATURES... Hurricane Erick is centered near 12.7N 140.0W at 0300 UTC moving W at 16 kt. Estimated minimum central pressure is 990 mb. Maximum sustained wind speed has increased to 65 kt with gusts to 80 kt. Numerous moderate to strong convection is noted within 75 nm N and 90 nm S semicircles, while scattered moderate to strong is found elsewhere from 08N to 15N between 136W and 140W. Erick continues to strengthen, and could potentially become a major hurricane late Tuesday or Wednesday. A weakening trend is forecast to then begin by Wednesday night. Please see latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Tropical Storm Flossie is centered near 12.3N 117.8W at 0300 UTC moving W at 15 kt. Estimated minimum central pressure is 1001 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Numerous strong convection is noted within 60 nm of center, while scattered moderate to strong is found elsewhere from 08N to 14.5N between 112W and 121W. Flossie is forecast to move westward overnight and continue to gradually strengthen, then reach hurricane force by Tuesday afternoon and begin a more WNW motion towards the Hawaiian Islands for the next several days. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 100W-101W N of 04N, moving W at 15 kt. Scattered to locally numerous moderate to strong convection is noted from 07.5N to 14N between 96W and 106W. The tropical wave previously analyzed near 124-125W has become stretched NW to SE over the past few days and is no longer well defined. An associated surface low is embedded within the monsoon trough near 10.5N122.5W, estimated at 1007 mb, drifting ESE. Scattered moderate to strong convection is within 90 nm E and 240 nm W semicircles of the low. The low will likely become absorbed across the southern portion of Flossie during the next few days. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N74W TO 09.5N99W TO 10.5N107W, then resumes from 11N120W TO low pres near 10.5N122.5W to 14N131W. Scattered moderate to strong convection is noted within 60 nm N and 180 nm S of the monsoon trough east of 95W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak ridge will dominate the waters west of Baja California through Thu, producing gentle to moderate winds. Fresh to strong gap winds prevailing across the Gulf of Tehuantepec have begun to diminish and will pulse to fresh to strong during the overnight and early morning hours hours in a very narrow plume through Thu night. A surface trough will meander between Baja California and the Gulf of California. This will result in fresh southerly winds across far north portions of the Gulf through Tue morning. Elswhere mainly gentle to moderate southerly winds will prevail through Tue, and then light and variable winds the remainder of the forecast period. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong gap winds will prevail across and extend well downstream of the Gulf of Papagayo through tonight, with seas in the 6 to 8 ft range. Gentle to moderate NE to E winds will prevail elsewhere N of the monsoon trough. Gentle to moderate S to SW winds are expected south of the monsoon trough. REMAINDER OF THE AREA... Please, see Special Features section for more information on Hurricane Erick, and T.S. Flossie. Elsewhere, a ridge prevails across the forecast waters N of 20N W of Baja California. The pressure gradient between the ridge and a couple of tropical cyclones moving westward S of the ridge will result in moderate to fresh winds mainly N of 15N W of 118W.