National Hurricane Center Says 17th Storm Formed Sunday Afternoon East Of Florida…
BY: WEATHER TEAM | BocaNewsNow.com
BOCA RATON, FL (BocaNewsNow.com) (Copyright © 2021 MetroDesk Media, LLC) — The National Hurricane Center just announced that Rose, the 17th storm of the season, formed.
Rose joins Peter — a tropical storm that formed in the early morning hours of Sunday.
Two additional systems, one off the coast of Africa, and another off the Northeastern United States, are being watched by forecasters for possible formation.
While paths and tracks can change, none of the systems — as of Sunday afternoon — appear to be a threat to the United States.
This is the official Rose forecast, filed by the NHC Sunday afternoon:
Satellite images show that deep convection has increased in coverage near the low-level center during the last 6 hours, while the overall structure of the tropical cyclone has also improved. Based on the improved organization and consensus T-2.5 numbers from TAFB and SAB, the initial intensity is set to 35 kt, making Rose the seventeenth named storm of the busy 2021 Atlantic hurricane season. Only 2005 and 2020 have had the seventeenth named storm on an earlier date. The 12-hour motion is north-northwest, or 330/14. However, Rose appears to be moving more in a northwest direction during the past few hours. This is probably the start of a northwest motion that should continue through day 4 as the system moves along the southwestern and western periphery of a subtropical ridge that extends from Africa across the Cabo Verde Islands. A turn to the north is predicted in about 5 days, as Rose comes under the influence of a strong mid-level trough approaching from the northwest. No significant changes were made to the previous track forecast. Environmental conditions are conducive for strengthening during the next day or so, with low wind shear, SSTs near 27C, and sufficient mid-level atmospheric moisture. Therefore, a little more strengthening is shown compared to the previous NHC forecast. The new NHC forecast is in agreement with the various consensus aids, but slightly below the SHIPS model, in deference to the global models which show a weaker cyclone. Westerly wind shear will likely increase in about 36 hours as a strong upper-level trough approaches from the northwest. Given that the cyclone is forecast to remain rather small, it will likely be vulnerable to the higher shear so weakening is forecast in the 36-72 h time period. Beyond day 3, a further increase in wind shear is expected to cause Rose to weaken to a tropical depression. Although not explicitly forecast, it is possible that the cyclone could become a remnant low in 4-5 days if the shear is too much for the system to handle. FORECAST POSITIONS AND MAX WINDS INIT 19/2100Z 14.3N 29.9W 35 KT 40 MPH 12H 20/0600Z 15.9N 31.4W 40 KT 45 MPH 24H 20/1800Z 17.9N 33.3W 45 KT 50 MPH 36H 21/0600Z 20.0N 34.8W 45 KT 50 MPH 48H 21/1800Z 22.0N 36.0W 40 KT 45 MPH 60H 22/0600Z 23.5N 37.0W 40 KT 45 MPH 72H 22/1800Z 24.7N 38.0W 35 KT 40 MPH 96H 23/1800Z 26.7N 40.6W 30 KT 35 MPH 120H 24/1800Z 28.7N 41.2W 30 KT 35 MPH
This is the Peter Discussion:
Over the past few hours deep convection with cloud tops as cold as -85 degrees C have developed near and to the east of the center of Peter. An Air Force Reserve Hurricane Hunter aircraft investigating the system earlier provided data during several legs of the flight that confirmed an intensity of 40 kt. A blend of the latest Dvorak T- and CI- numbers from TAFB are consistent with that data, and therefore the initial intensity remains 40 kt for this advisory. The vertical wind shear that stripped Peter of its deep convection earlier today is forecast to increase further through tonight and persist for at least a few days. Global model simulated satellite imagery suggests this latest burst of convection will also become removed from the center within several hours, with the cyclone struggling to maintain persistent deep convection throughout much of the 5-day forecast period. Therefore, despite being over very warm waters, Peter is forecast to slowly weaken over the next several days. The intensity model guidance is in decent agreement on this scenario, and the NHC forecast remains near the various intensity consensus solutions. As mentioned in the previous discussion, there are some indications, particularly by the GFS, that Peter could open back into a wave within a few days which adds some additional uncertainty to the intensity forecast. Peter's initial motion remains 290/15 kt. The storm is forecast to continue to move in this west-northwestward direction for the next couple of days as it is steered to the south of a subtropical ridge. This ridge is expected to weaken in a few days which should cause the cyclone to slow its forward motion and turn northwestward. Late in the forecast period a turn to the north and possibly northeast is expected to occur as Peter gets caught in the flow around a large trough to its north. The model guidance has shifted westward beyond day 2, in part due to a faster forward motion. While the timing of the cyclone's turn to the north remains the same, the NHC forecast was shifted to the left beyond 48 h, but still remains to the east of the consensus. Based on the track, intensity, and wind radii forecast, no tropical storm watches or warnings are required for the northern Leeward Islands, Virgin Islands or Puerto Rico. However, interests there should monitor the progress of the system as locally heavy rain is possible on Monday and Tuesday when it is expected to pass to the north of the area. Key Messages: 1. Rainfall around the southern periphery of Tropical Storm Peter may lead to areas of urban and small stream flooding from late today into Tuesday across Puerto Rico, the Virgin Islands, and the Northern Leeward Islands. FORECAST POSITIONS AND MAX WINDS INIT 19/2100Z 18.4N 57.8W 40 KT 45 MPH 12H 20/0600Z 19.1N 59.8W 40 KT 45 MPH 24H 20/1800Z 19.9N 62.1W 35 KT 40 MPH 36H 21/0600Z 20.8N 64.3W 35 KT 40 MPH 48H 21/1800Z 21.9N 66.0W 35 KT 40 MPH 60H 22/0600Z 22.9N 67.2W 35 KT 40 MPH 72H 22/1800Z 24.1N 68.2W 30 KT 35 MPH 96H 23/1800Z 26.1N 68.3W 30 KT 35 MPH 120H 24/1800Z 27.7N 67.5W 30 KT 35 MPH
And this is the outlook for additional systems:
For the North Atlantic...Caribbean Sea and the Gulf of Mexico: The National Hurricane Center is issuing advisories on Tropical Storm Peter, located several hundred miles east of the northernmost Leeward Islands, and on Tropical Depression Seventeen, located a few hundred miles west-southwest of the southernmost Cabo Verde Islands. 1. A tropical wave located along the west coast of Africa is forecast to emerge offshore this evening. Environmental conditions appear conducive for gradual development over the next several days, and a tropical depression could form late this week as it moves westward at 10 to 15 mph across the eastern and central tropical Atlantic Ocean. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 5 days...medium...40 percent. 2. A gale force non-tropical low pressure system, the remnants of Odette, is located a few hundred miles south of Newfoundland. This system could acquire some subtropical or tropical characteristics by the middle of this week as it moves slowly eastward and then southeastward over warmer waters across the north-central Atlantic Ocean. Additional information on this system, including storm warnings, can be found in High Seas Forecasts issued by the National Weather Service. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 5 days...low...30 percent. Public Advisories on Tropical Storm Peter are issued under WMO header WTNT31 KNHC and under AWIPS header MIATCPAT1. Forecast/Advisories on Tropical Storm Peter are issued under WMO header WTNT21 KNHC and under AWIPS header MIATCMAT1. Public Advisories on Tropical Depression Seventeen are issued under WMO header WTNT32 KNHC and under AWIPS header MIATCPAT2. Forecast/Advisories on Tropical Depression Seventeen are issued under WMO header WTNT22 KNHC and under AWIPS header MIATCMAT2. High Seas Forecasts issued by the National Weather Service can be found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php
