National hurricane center Monday September 20 2021

HURRICANE CENTER MONDAY: Peter, Rose And Another System East Of Florida

Florida hurricane News weather
Print Friendly, PDF & Email

Now Four Systems In The Atlantic.

Tropical outlook for Monday, September 20, 2021.

BY: WEATHER TEAM | BocaNewsNow.com

BOCA RATON, FL (BocaNewsNow.com) (Copyright © 2021 MetroDesk Media, LLC) — Monday morning is bringing four systems for the National Hurricane Center to monitor, three are directly east of Florida.

Peter, Rose and a third system — unnamed so far — are all being monitored by the National Hurricane Center. The orange X above has a 60 percent chance of developing over the next five days.

The yellow X is what’s left of Odette. It is expected to dissipate today.

Neither Peter nor Rose are expected to directly impact Florida — both are expected to turn to the north or northwest over the next several days. Even so, it’s important to watch these storms.

This is the tropical outlook for early Monday morning, followed by the forecasts for Peter and Rose.

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical 
Storm Peter, located a few hundred miles east of the northernmost 
Leeward Islands, and on Tropical Storm Rose, located several hundred 
miles west of the southernmost Cabo Verde Islands.

1. A tropical wave located over the far eastern tropical Atlantic 
several hundred miles southeast of the Cabo Verde Islands is 
producing an area of disorganized showers and thunderstorms.  
Environmental conditions appear conducive for gradual development 
over the next several days, and a tropical depression could form 
later this week while the system moves westward at 10 to 15 mph 
across the eastern and central tropical Atlantic Ocean.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...60 percent.

2. A storm-force, non-tropical low pressure system, the remnants 
of Odette, is located a couple of hundred miles southeast of 
Newfoundland.  This low could acquire some subtropical 
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.
Tropical Storm Rose for Monday, September 20, 2021.

Tropical Storm Rose:

Rose remains a sheared tropical storm with the low-level center 
located near the eastern edge of the convective cloud mass based on 
an earlier 0359Z AMSR2 microwave overpass. These same data also 
revealed that a well-defined mid-level circulation center was 
located about 80-90 nmi west of the low-level center, an indication 
of the magnitude and effect of the mid-level shear impinging on the 
cyclone. The intensity of 35 kt is being maintained for this 
advisory based on subjective Dvorak satellite intensity estimates of 
35 from both TAFB and SAB. Objective estimates from UW-CIMSS are 
higher at 45-55 kt, which are considered to be unrepresentative due 
to the severe westward tilt of Rose's vortex column.

The initial motion estimate is northwestward or 315/13 kt.  Rose is 
expected to move generally northwestward around the southwestern and 
western periphery of a strong subtropical ridge during the next few 
days.  By day 4 and beyond, a mid- to upper-level trough over the 
north-central Atlantic is forecast to dig southeastward, causing the 
cyclone to turn northward.  The latest NHC model guidance remains in 
excellent agreement on this track scenario through 72 hours, but 
then diverge significantly thereafter owing to whether Rose weakens 
to shallow system or remains a little stringer and deeper. The 
weaker solutions go more toward the northwest and the stronger 
solutions take Rose northeastward. The NHC forecast track on days 4 
and 5 is a blend of these two extremes. 

Rose only has about 24 hours over warm waters and in a weak vertical 
wind shear regime that will allow for some addition strengthening to 
occur. On days 2-5, however, increasing westerly shear is expected 
to induce some gradual weakening.  Rose is forecast to weaken to a 
tropical depression by 96 hours, although some of the models suggest 
that weakening could occur faster than indicated below, and that 
Rose could degenerate into a remnant low by the end of the forecast 
period.


FORECAST POSITIONS AND MAX WINDS

INIT  20/0900Z 15.9N  32.6W   35 KT  40 MPH
 12H  20/1800Z 17.5N  33.8W   40 KT  45 MPH
 24H  21/0600Z 19.8N  35.5W   40 KT  45 MPH
 36H  21/1800Z 21.7N  36.7W   35 KT  40 MPH
 48H  22/0600Z 23.0N  37.7W   35 KT  40 MPH
 60H  22/1800Z 24.2N  38.7W   35 KT  40 MPH
 72H  23/0600Z 25.2N  39.8W   30 KT  35 MPH
 96H  24/0600Z 27.3N  41.3W   25 KT  30 MPH
120H  25/0600Z 29.2N  40.6W   25 KT  30 MPH

Tropical Storm Peter:

Tropical Storm Peter for Monday, September 20, 2021.
Peter is a strongly sheared tropical storm. Reconnaissance wind 
data, conventional satellite imagery, and passive microwave 
satellite data indicate that Peter's center is located just to the 
west of the deep convection. Data from the aircraft support holding 
the intensity at 45 kt for now based on 925-mb flight-level and 
SFMR winds of 53 kt and 41 kt, respectively, on their last leg when 
the aircraft came in from the northeast. The central pressure had 
also increased only slightly to 1006 mb.

Peter has continued to move west-northwestward, or 295/12 kt. There 
are no significant changes to the previous track forecast or 
reasoning. Peter is expected to move around the southwestern and 
western periphery of a subtropical ridge for the next couple of 
days, followed by a slow northward motion on days 3-5 as the 
cyclone moves through a weakness in the ridge induced by the 
southward-moving former Tropical Storm Odette. The new NHC track 
forecast is very similar to the previous advisory track, and lies 
just to the east of the tightly packed consensus track models. 

Some fluctuations in intensity will be possible during the next 
24-36 hours owing to 5-10 kt fluctuations in the magnitude and also 
the direction of the deep-layer vertical wind shear. However, by 48 
hours and beyond, a slow weakening trend is expected due to the 
shear increasing from the southwest and west-southwest of near 30 
kt. The new official intensity forecast is essentially just an 
update of the previous advisory, and closely follows the IVCN and 
HCCA intensity consensus models.

Based on the latest track, intensity, and wind radii forecasts, no
tropical storm watches or warnings are required for the northern
Leeward Islands, Virgin Islands, or Puerto Rico at this time.
However, locally heavy rain is possible on Monday and Tuesday when
Peter is expected to pass to the north of these locations.


Key Messages:

Rainfall around the southern periphery of Tropical Storm Peter may 
lead to areas of urban and small stream flooding through Tuesday 
across Puerto Rico, the Virgin Islands, and the Northern Leeward 
Islands.


FORECAST POSITIONS AND MAX WINDS

INIT  20/0900Z 19.1N  59.5W   45 KT  50 MPH
 12H  20/1800Z 19.7N  61.4W   40 KT  45 MPH
 24H  21/0600Z 20.4N  63.6W   40 KT  45 MPH
 36H  21/1800Z 21.4N  65.5W   35 KT  40 MPH
 48H  22/0600Z 22.4N  67.2W   35 KT  40 MPH
 60H  22/1800Z 23.2N  68.0W   30 KT  35 MPH
 72H  23/0600Z 24.2N  68.4W   30 KT  35 MPH
 96H  24/0600Z 26.2N  67.8W   25 KT  30 MPH
120H  25/0600Z 28.5N  66.8W   30 KT  35 MPH

Content copyright © 2021 Metro Desk Media, LLC. All Rights Reserved. We vigorously protect our intellectual property and journalistic product. Broadcast stations must credit BocaNewsNow.com on air. Print must refer to BocaNewsNow.com. Online must link to BocaNewsNow.com. We have agreements with several organizations. Contact news (at) bocanewsnow.com.

News. Free. As It Happens. Subscribe To Our Updates.

Tagged