🚨 Montgomery: None     🚨 Lee; Phillips; Tunica; Coahoma; Quitman; Tallahatchie: Heat Advisory issued August 20 at 12:36PM CDT until August 20 at 8:00PM CDT by NWS Memphis TN     🚨 Yalobusha; Calhoun; Chickasaw; Monroe: Heat Advisory issued August 20 at 12:36PM CDT until August 20 at 8:00PM CDT by NWS Memphis TN     🚨 Lee; Phillips; Tunica; Coahoma; Quitman; Tallahatchie: Heat Advisory issued August 20 at 12:36PM CDT until August 21 at 8:00PM CDT by NWS Memphis TN     🚨 St. Francis; Tate; Panola; Lafayette; Union; Pontotoc; Lee; Itawamba: Heat Advisory issued August 20 at 12:36PM CDT until August 20 at 8:00PM CDT by NWS Memphis TN     🚨 Yalobusha; Calhoun; Chickasaw; Monroe: Heat Advisory issued August 20 at 12:36PM CDT until August 21 at 8:00PM CDT by NWS Memphis TN     🚨 Fairfield; Kershaw; Southern Lancaster: Special Weather Statement issued August 20 at 1:34PM EDT by NWS Columbia SC     🚨 Sussex; Surry; Southampton: Special Weather Statement issued August 20 at 1:33PM EDT by NWS Wakefield VA     🚨 Perry, OH: Flood Warning issued August 20 at 1:33PM EDT until August 20 at 5:45PM EDT by NWS Charleston WV     🚨 Hutchinson; Roberts; Hemphill; Gray; Wheeler; Armstrong; Donley: Heat Advisory issued August 20 at 12:33PM CDT until August 21 at 9:00PM CDT by NWS Amarillo TX    

Active Tropical Systems & Formation Outlook

A whole-basin summary of all active tropical cyclones and the NHC Tropical Weather Outlook, generated with the tropycal package. Select a storm below for its official forecast and model guidance.

Summary & NHC 7-Day Formation Outlook

Valid: 17 UTC 20 Aug 2026

Active storms summary

Select a Storm

LALA (CP012026)

Type: HU Max Wind: 85 kt Min Pressure: 969 hPa Position: 23.8, -172.0 Basin: East Pacific

TWO (CP022026)

Type: TD Max Wind: 30 kt Min Pressure: 1006 hPa Position: 11.7, -142.6 Basin: East Pacific

SAUDEL (WP172026)

Type: TS Max Wind: 40 kt Min Pressure: 996 hPa Position: 12.8, 150.2 Basin: West Pacific
HAFS and GEFS guidance is only available for storms in the US/NHC domain (Atlantic & East/Central Pacific). For this system, the basin summary and best-track position are shown.
WDPN31 PGTW 201500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 17W (SAUDEL) WARNING NR 009// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 12.8N 150.2E INITIAL INTENSITY: 40 KTS GEOGRAPHIC REFERENCE: 314 NM EAST OF ANDERSEN AFB MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 11 KTS SIGNIFICANT WAVE HEIGHT: 18 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL STORM (TS) 17W IS NOW INTENSIFYING. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS EXPLOSIVE CENTRAL CONVECTION, WITH CLOUD TOP TEMPERATURES AS COLD AS -86 DEGREES CELSIUS, WRAPPING INTO THE LOW-LEVEL CIRCULATION CENTER. SURROUNDING THIS CORE CONVECTION, OUTER FEEDER BANDS ARE SHOWING INCREASING CURVATURE AND EXTENT. DESPITE THE PRESENCE OF MODERATE NORTHEASTERLY SHEAR IN THE 850-400 MB LAYER, THE UPPER-LEVEL OUTFLOW IS EXPANDING RADIALLY, INDICATING THAT THE SYSTEM IS SUCCESSFULLY OVERCOMING THE SHEAR. A FORTUITOUS 201101Z ASCAT-B PASS REVEALED UNFLAGGED 35-40 KT WINDS IN THE SOUTHEAST QUADRANT AND CONFIRMED A WIND FIELD THAT IS GRADUALLY BECOMING MORE SYMMETRIC. THE SURROUNDING ENVIRONMENT IS FAVORABLE FOR FURTHER DEVELOPMENT, CHARACTERIZED BY VERY WARM SEA SURFACE TEMPERATURES (SST) OF 30-31 DEGREES CELSIUS AND RICH, DEEP-LAYER MOISTURE. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE WELL-DEFINED CIRCULATION CENTER IN THE ASCAT-B PASS. THE INITIAL INTENSITY HAS BEEN RAISED TO 40 KTS, ALSO WITH HIGH CONFIDENCE, BASED ON THE SAME SCATTEROMETER DATA. PGTW, KNES, RJTD, AND RCTP HAVE PROVIDED SUBJECTIVE DVORAK FIXES OF T2.5, WHILE THE OBJECTIVE ESTIMATES FROM CIMSS LAG SLIGHTLY BEHIND. INITIAL WIND RADII BASIS: SCATTEROMETER DATA CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A LOW- TO MID-LEVEL RIDGE CENTERED AT 43N 173E AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS RJTD: T2.5 - 35 KTS RCTP: T2.5 - 35 KTS KNES: T2.5 - 35 KTS CIMSS SATCON: 39 KTS AT 200540Z CIMSS ADT: 32 KTS AT 201210Z CIMSS AIDT: 32 KTS AT 201210Z CIMSS D-MINT: 31 KTS AT 200720Z CIMSS D-PRINT: 41 KTS AT 201140Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 15-20 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 17W IS NOW MOVING NORTHWESTWARD AT 11 KTS, A MOTION THAT WILL PERSIST FOR THE NEXT 36 HOURS UNDER THE STEERING INFLUENCE OF A RIDGE POSITIONED TO ITS NORTHEAST. AFTER TAU 36, A DEEP-LAYER RIDGE OVER THE CENTRAL NORTH PACIFIC WILL MIGRATE WESTWARD, INDUCING A MORE WESTWARD TRACK. COMPLICATIONS ARISING FROM THE INTERACTION OF A MONSOON DEPRESSION, DESIGNATED AS 94W, WITH THE SUBTROPICAL RIDGE (STR) OVER HONSHU RESULT IN SIGNIFICANT FORECAST TRACK UNCERTAINTY AT TAU 96 AND TAU 120. A SPECTRUM OF POSSIBLE TRACKS EXIST THAT DEPEND ON THE STRENGTH OF THE STR. ON ONE END OF THE SPECTRUM, THE MONSOON DEPRESSION REMAINS WEAK, ALLOWING FOR A STRONGER STR. THIS WOULD LEAD TO A ZONAL TRAJECTORY TOWARD THE SOUTHERN RYUKYU ISLANDS. THE OTHER END PRESENTS A STRONGER 94W, WHICH CREATES A WEAKNESS IN THE STR THAT WOULD ALLOW TS 17W TO TURN POLEWARD INTO SHIKOKU. THE JTWC FORECAST TRACK FAVORS THE FORMER SOLUTION AND DEPICTS A MORE ZONAL TRACK. THE CONVECTION ASSOCIATED WITH TS 17W IS EXPANDING RAPIDLY, AND THE SYSTEM IS ON THE PRECIPICE OF A PROLONGED PERIOD OF VERY RAPID INTENSIFICATION (RI). THE ENVIRONMENTAL CONDITIONS ONLY GET BETTER FROM THIS POINT FORWARD, WITH OCEAN HEAT CONTENT (OHC) INCREASING TO 125-150 KJ PER CM2 AND VERTICAL WIND SHEAR (VWS) DECREASING TO 5-10 KTS. ADDITIONALLY, AFTER TAU 12, THE SYSTEM WILL TAP INTO A POLEWARD OUT…

95W (WP952026)

Type: TD Max Wind: 25 kt Min Pressure: 996 hPa Position: 19.8, 109.2 Basin: West Pacific
HAFS and GEFS guidance is only available for storms in the US/NHC domain (Atlantic & East/Central Pacific). For this system, the basin summary and best-track position are shown.

ECMWF 10-m Streamlines

This map visualizes near-surface winds from the ECMWF operational model using streamlines — continuous curves that show the direction of the wind at every point. Streamlines help us visually detect patterns of atmospheric flow, such as jets, troughs, and areas of rotation.

Forecasters at the NHC monitor 10-meter wind fields for signs of a closed low-level circulation — a common feature of early tropical cyclone formation. When streamlines wrap into a tight, circular pattern and form a closed loop, it may signal that a system is transitioning from a disorganized disturbance into a structured cyclone.

This early organization of wind flow is a key threshold in classifying an area as a potential tropical cyclone. While other ingredients like convection and mid-level humidity are also necessary, closed low-level circulation is often the first structural milestone forecasters look for.

Look for small, circular loops in the streamlines over oceanic regions — especially where other environmental factors also align for storm formation.

Streamline Wind Map

ECMWF Predictions

No active storm found in ECMWF data at this time.

Environmental Indicators

Hypothetical TC Drift Paths

This map displays hypothetical tropical cyclone (TC) paths projected from genesis-favorable zones identified by an environmental mask. These paths are computed using the Emanuel Beta and Advection Model, a physically based framework that estimates the motion of nascent cyclones by combining steering-level winds and planetary rotation effects.

The model blends winds from two critical pressure levels — 850 hPa (lower troposphere) and 250 hPa (upper troposphere) — weighted toward the lower level where most of a tropical cyclone's mass resides. It also incorporates a background component associated with beta drift, which arises from the variation of the Coriolis force with latitude.

Each pink trajectory represents a storm initialized from a grid cell where all five environmental thresholds were favorable: high CAPE, low vertical wind shear, high mid-level humidity, warm SSTs, and positive low-level vorticity. Arrows darken with time, tracing the cyclone’s evolution in 6-hour steps. These tracks can move over land given the steering winds, but in reality these storms weaken quickly when no longer over warm water. This means the tracks that move over significant would likely die out quickly and are not well represented in this model.

Hypothetical storms often drift westward and poleward, steered by large-scale tropical flow and Earth's rotation — this helps forecasters anticipate where early-stage disturbances might evolve into organized storms.

TC Drift Path Map

Pressure & Rainfall (hPa)

This chart shows 24-hour forecasts of surface pressure (in hPa) and precipitation (in mm) for select U.S. cities. The data comes from the Open-Meteo API, which sources its predictions from high-resolution numerical weather models like ICON (from the German Weather Service) and ECMWF's IFS. These are advanced general circulation models (GCMs) that solve physical equations governing the atmosphere — including thermodynamics, fluid motion, and radiation — to simulate and forecast future states of weather.

A sudden drop in pressure may signal the approach of a developing storm system. Increasing rainfall intensity often tracks with tropical activity or frontal systems. These paired indicators help visualize evolving atmospheric instability and potential hazards.

NBDC Gulf Buoy Data

This data comes from the National Data Buoy Center (NDBC), a division of NOAA responsible for monitoring ocean and atmospheric conditions using moored buoys, coastal stations, and drifting floats. These sensors play a vital role in tracking tropical cyclone development by recording variables like wind speed, barometric pressure, air & sea surface temperatures, and wave height — all of which help determine storm structure and intensification.

A sudden drop in sea-level pressure or a spike in wind gusts can signal rapid cyclone strengthening. Water temperature above ~26°C is a key fuel source for tropical cyclones. Wave and swell height give insight into the storm’s reach and energy transfer across the ocean. Monitoring these in real time helps improve forecasts and early warnings.

Wind: NW (320°), 1.9 kt   |   Gust: 1.9 kt

Pressure: 30.09   |   Air Temp: 87.4 °F

Water Temp: 88.0 °F   |   Dew Point: 78.8 °F

Swell:   |   Wind Wave:

NWS U.S. Radar

The National Weather Service (NWS) collects radar data using the NEXRAD (Next Generation Radar) network — a nationwide system of over 150 high-resolution Doppler radar stations. Radar works by emitting pulses of energy that bounce off precipitation (like raindrops, hail, or snow) and return to the radar dish. Doppler radar not only detects the location and intensity of storms, but also their motion — by measuring shifts in frequency caused by movement of particles toward or away from the radar site. This allows meteorologists to spot rotating storms and potential tornadoes in real time.

US National Radar Loop

GOES 15-min Satellite

The GOES (Geostationary Operational Environmental Satellite) system is operated by NOAA and provides continuous weather observation over the Americas. Orbiting 22,300 miles above Earth, GOES satellites deliver high-resolution imagery every 15 minutes, helping track tropical systems, cloud formation, and atmospheric motion in real time. The Geocolor imagery shown here combines visible and infrared data to highlight clouds, land, and sea in a natural-looking format.

Satellite

GOES Band 13 – Infrared (IR) Imagery

Band 13 (10.3 µm) is one of the most important infrared channels for tropical meteorology, measuring emitted radiation from cloud tops. Colder colors (red, yellow) signal deep convection, where strong thunderstorms punch through the upper atmosphere. These features often indicate the early stages of tropical cyclone formation.

GOES IR Band 13

Most recent GOES Band 13 image. Provided by NOAA/NESDIS/STAR.