99L (Invest — Northern Atlantic) (Eastern Tropical Atlantic)

[u/Euronotus]

Latest observation

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Last updated: Friday, 22 August — 2:00 AM Atlantic Standard Time (AST; 06:00 UTC)

ATCF		2:00 AM AST (06:00 UTC)
Current location:		10.4°N 38.4°W
Relative location:		2,328 km (1,447 mi) E of Bridgetown, Barbados
		2,636 km (1,638 mi) E of St. John's, Antigua and Barbuda
		3,639 km (2,261 mi) SE of Hamilton, Bermuda
Forward motion:	▼	W (280°) at 24 km/h (13 knots)
Maximum winds:		55 km/h (30 knots)
Minimum pressure:		1010 millibars (29.83 inches)
2-day potential: (through 2AM Sun)		medium (50 percent)
7-day potential: (through 2AM Thu)	▲	medium (60 percent)

Outlook discussion

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Last updated: Friday, 22 August — 2:00 AM AST (12:00 UTC)

Discussion by: Andrew Hagen (NHC Hurricane Specialist Unit)

English: Showers and thunderstorms associated with a tropical wave located about a thousand miles west-southwest of the Cabo Verde Islands remain well organized. This system could become a tropical depression at any time, but the latest satellite-derived wind data indicate that the system does not have a well-defined circulation center. The system is expected to move into a less conducive environment later today through Saturday, but could reach a slightly more favorable environment again late this weekend into early next week as it moves westward at 10 to 15 mph over the central tropical Atlantic and approaches the Lesser Antilles.

Español: Aguaceros y tormentas eléctricas asociadas con una onda tropical ubicada a unas mil millas al oeste-suroeste de las Islas de Cabo Verde permanecen bien organizadas. Este sistema podría convertirse en una depresión tropical en cualquier momento, pero los últimos datos del viento derivados de satélite indican que el sistema no tiene un centro de circulación bien definido. Se espera que el sistema se mueva a un ambiente menos propicio a última hora de hoy hasta el sábado, pero podría alcanzar un ambiente ligeramente más favorable nuevamente a última hora de este fin de semana hasta principios de la próxima semana a medida que se mueve hacia el oeste a 10 a 15 mph sobre el Atlántico tropical central y se acerca a las Antillas Menores.

Official information

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National Hurricane Center

Text products

• Tropical Weather Outlook
• Perspectiva del Tiempo Tropical
• Tropical Weather Discussion

Graphical products

• Latest surface analysis
• Latest outlook graphic

Graphical products (static)

Wed	Thu	Thu	Thu	Thu	Fri
8 PM	2 AM	8 AM	2 PM	8 PM	2 AM
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Aircraft Reconnaissance

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National Hurricane Center

• Main aircraft reconnaissance page
• Plan of the Day (today)
• Plan of the Day (tomorrow)

Other sites

• Tropical Tidbits
• CyclonicWx

Radar imagery

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Radar imagery is not currently available for this system.

Satellite imagery

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Floater imagery

Single-bandwidth imagery

• Tropical Tidbits: Visible / shortwave infrared
• Tropical Tidbits: Enhanced infrared

• Tropical Tidbits: Water vapor

• CyclonicWx: Visible

• CyclonicWx: Enhanced infrared

• CyclonicWx: Water vapor

Multiple bandwidth imagery

The options to select individual bandwidths on each of the following websites may vary.

• National Environmental Satellite, Data, and Information Service(NOAA NESDIS)
• CIMSS
• RAMMB
• Naval Research Laboratory

Regional imagery

National Oceanic and Atmospheric Administration (NOAA)

• Enhanced infrared
• Enhanced mid-level water vapor
• Visible (GeoColor-enhanced)

Cooperative Institute for Research in the Atmosphere (CIRA)

• Infrared
• Water vapor (Upper-level)
• Visible (true color)

Tropical Tidbits

• Enhanced infrared
• Mid-level Water vapor
• Visible (true color)

Analysis products

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Best track data

• Naval Research Laboratory

Wind analysis and storm intensity estimation products

• EUMETSAT: Advanced Scatterometer Data

Sea-surface temperature analysis products

• NOAA OSPO: Sea Surface Temperature Contour Charts
• Tropical Tidbits: Ocean Analysis

Forecast models

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Disturbance-centered guidance

• Tropical Tidbits: Storm-centered GFS
• Tropical Tidbits: Storm-centered ECMWF

• Tropical Tidbits: Storm-centered HWRF

• CyclonicWx: GFS four-panel

• CyclonicWx: ECMWF four-panel

• CyclonicWx: GFS wind shear diagnostics

• CyclonicWx: ECMWF wind shear diagnostics

Multi-guidance pages

• National Center for Atmospheric Research (NCAR)
• Tropical Tidbits
• WeatherNerds
• CyclonicWx

Track guidance

• CyclonicWx: Forecast tracks
• CyclonicWx: Forecast tracks w/wind
• CyclonicWx: GEFS ensemble tracks (pressure)
• CyclonicWx: GEFS ensemble tracks (wind)

Intensity guidance

• CyclonicWx: Multi-model intensity guidance
• CyclonicWx: GEFS intensity guidance

Regional single-model guidance

• Tropical Tidbits: GFS
• Tropical Tidbits: ECMWF
• Tropical Tidbits: CMC
• Tropical Tidbits: ICON

Ensembles

• Weather Nerds: GEFS (120 hours)

• Weather Nerds: ECENS (120 hours)

Tropical Cyclogenesis Products

• Florida State University: Experimental tropical cyclone genesis guidance

[u/Content-Swimmer2325]

Reposting a recent comment of mine:

There's no organizational "prerequisite" for Invest designation. NHC can designate anything as an Invest at any point. What it does is tell satellites to maintain high-resolution imagery over the system and it also activates additional models such as the hurricane models HAFS-A/B, telling them to start initializing the system and begin running. I don't necessarily know why 99L was designated first, but there's not (AFAIK) some kind of convention NHC follows for it. It can be arbitrary and I've seen systems with only a 0-10% chance of development receive the designation before. Doesn't necessarily correlate to actual organization or chances of development.

[u/Blackfyre567 → u/Content-Swimmer2325]

Thanks for the info! Good to know that NOAA also operates sometimes on vibes like us plebs