🚨 Delaware, OH; Fairfield, OH; Franklin, OH; Licking, OH: Flood Warning issued August 20 at 7:29AM EDT until August 20 at 1:30PM EDT by NWS Wilmington OH     🚨 Montgomery: None     🚨 Vance; Warren; Halifax; Franklin; Nash; Edgecombe; Wake; Johnston; Wilson; Harnett; Wayne; Scotland; Hoke; Cumberland; Sampson: Special Weather Statement issued August 20 at 7:26AM EDT by NWS Raleigh NC     🚨 Tinian; Saipan: Tropical Storm Watch issued August 20 at 9:26PM ChST by NWS Tiyan GU     🚨 Choctaw; Washington; Clarke; Wilcox; Monroe; Conecuh; Butler; Crenshaw; Escambia; Covington; Mobile Inland; Baldwin Inland; Mobile Central; Baldwin Central; Mobile Coastal; Baldwin Coastal; Escambia Inland; Escambia Coastal; Santa Rosa Inland; Santa Rosa Coastal; Okaloosa Inland; Okaloosa Coastal; Wayne; Perry; Greene; Stone; George: Heat Advisory issued August 20 at 6:24AM CDT until August 20 at 8:00PM CDT by NWS Mobile AL     🚨 Preble, OH: Flood Warning issued August 20 at 7:23AM EDT until August 20 at 2:00PM EDT by NWS Wilmington OH     🚨 Delaware, OH; Franklin, OH: Flood Advisory issued August 20 at 7:18AM EDT until August 20 at 8:00PM EDT by NWS Wilmington OH     🚨 Dawson: Dense Fog Advisory issued August 20 at 6:18AM CDT until August 20 at 10:00AM CDT by NWS Hastings NE     🚨 Smith; Jewell; Valley; Greeley; Nance; Sherman; Howard; Merrick; Polk; Buffalo; Hall; Hamilton; York; Kearney; Adams; Clay; Fillmore; Franklin; Webster; Nuckolls; Thayer: Dense Fog Advisory issued August 20 at 6:18AM CDT until August 20 at 10:00AM CDT by NWS Hastings NE     🚨 Loup; Custer; Lincoln: Dense Fog Advisory issued August 20 at 6:17AM CDT until August 20 at 10:00AM CDT by NWS North Platte NE    

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: 11 UTC 20 Aug 2026

Active storms summary

Select a Storm

LALA (CP012026)

Type: HU Max Wind: 95 kt Min Pressure: 963 hPa Position: 23.1, -171.8 Basin: East Pacific

90E (EP902026)

Type: DB Max Wind: 30 kt Min Pressure: 1007 hPa Position: 10.9, -141.1 Basin: East Pacific
2-Day Formation: 90% (High) 5-Day Formation: N/A (N/A)

SAUDEL (WP172026)

Type: TS Max Wind: 35 kt Min Pressure: 997 hPa Position: 11.9, 150.9 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 200900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 17W (SAUDEL) WARNING NR 008// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 11.9N 150.9E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 367 NM EAST-SOUTHEAST OF ANDERSEN AFB MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 06 KTS SIGNIFICANT WAVE HEIGHT: 16 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN ELONGATED LOW-LEVEL CIRCULATION CENTER (LLCC), WHICH IS PARTIALLY OBSCURED BY PERSISTENT DEEP CONVECTION ALONG THE SOUTHERN PERIPHERY. MORE RECENTLY, NEW CONVECTION HAS FLARED UP OVER THE NE QUADRANT, A SIGN THAT THE SYSTEM WILL BEGIN TO BECOME MORE SYMMETRIC. TROPICAL STORM (TS) 17W HAS BEEN STRUGGLING TO INTENSIFY LARGELY DUE TO ITS HIGHLY ASYMMETRIC STRUCTURE AND THE PRESENCE OF LIGHT TO MODERATE NORTHEASTERLY MID-LEVEL SHEAR. A 200348Z AMSR2 37 GHZ IMAGE CONFIRMS THIS POOR ORGANIZATION, REVEALING A LACK OF AN INNER CORE AND DISORGANIZED CONVECTIVE BANDING. THE ENVIRONMENT IS FAVORABLE FOR DEVELOPMENT, CHARACTERIZED BY VERY WARM SEA SURFACE TEMPERATURES (SST) OF 29-30 DEGREES CELSIUS AND EXPANDING UPPER-LEVEL OUTFLOW. THESE FACTORS ARE OFFSET BY THE MODEST VERTICAL WIND SHEAR (VWS). THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE PARTLY EXPOSED LLCC VISIBLE IN THE MSI. REFLECTING THE SYSTEM'S CONTINUED POOR ORGANIZATION, THE INITIAL INTENSITY IS HELD AT 35 KTS WITH MEDIUM CONFIDENCE, WHICH ALIGNS WITH THE T2.5 SUBJECTIVE DVORAK FIXES FROM PGTW AND RJTD AND IS CONSISTENT WITH THE OBJECTIVE ESTIMATES FROM CIMSS RANGING FROM 30 KTS TO 39 KTS. INITIAL WIND RADII BASIS: SCATTEROMETER DATA CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A LOW- TO MID-LEVEL RIDGE CENTERED AT 35N 172E AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS RJTD: T2.5 - 35 KTS RCTP: T2.0 - 30 KTS KNES: T2.0 - 30 KTS CIMSS SATCON: 39 KTS AT 200540Z CIMSS ADT: 33 KTS AT 200610Z CIMSS AIDT: 35 KTS AT 200610Z CIMSS D-MINT: 30 KTS AT 200330Z CIMSS D-PRINT: 30 KTS AT 200540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE EASTWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: AFTER A WESTWARD JOG BETWEEN 191800Z AND 200000Z, TS 17W HAS RESUMED A NORTHWESTWARD TRAJECTORY ALONG THE SOUTHWESTERN PERIPHERY OF A LOW- TO MID-LEVEL RIDGE TO ITS NORTHEAST. THIS WESTWARD SHIFT HAS BROUGHT THE GALE-FORCE WIND RADII CLOSER TO SAIPAN AND TINIAN. A DEEP-LAYER RIDGE, ALSO CENTERED TO THE NORTHEAST, WILL BECOME THE DOMINANT STEERING INFLUENCE AFTER TAU 24 AS THE STORM MATURES. THIS RIDGE WILL THEN BEGIN TO SHIFT WESTWARD BY TAU 48, FORCING THE STORM ONTO A MORE WEST-NORTHWESTWARD TRACK. SIGNIFICANT FORECAST UNCERTAINTY ARISES DUE TO POTENTIAL INTERACTION WITH A MONSOON DEPRESSION, DESIGNATED AS 94W, IN THE EXTENDED PERIOD. IN ONE SCENARIO, 94W SIGNIFICANTLY WEAKENS THE SUBTROPICAL RIDGE (STR) OVER SOUTHERN HONSHU, ALLOWING TS 17W TO CURVE POLEWARD BY TAU 120. IF THE STR REMAINS INTACT, THEN THE SYSTEM WILL CONTINUE ITS NORTHWESTWARD TRAJECTORY TOWARD THE RYUKYU ISLANDS. THE LATTER SCENARIO IS FAVORED BY THE JTWC FORECAST. THE SYSTEM IS BEGINNING TO SHOW SIGNS OF ORGANIZATION, WITH NEW CONVECTION FIRING UP AND WRAPPING INTO THE LLCC. THE ENVIRONMENT AHEAD WILL BE HIGHLY FAVORABLE FOR INTENSIFICATION. WITHIN THE NEXT 12 HOURS, THE VWS WILL EASE TO BELOW 10 KTS. CONCURRENTLY, THE SYSTEM WILL TRAVERSE OVER INCREASING LEVELS OF HIGH OCEAN HEAT CONTENT (OHC) AND BEGIN TO TAP INTO A POLEWARD OUTFLOW CHANNEL IND…

95W (WP952026)

Type: TD Max Wind: 25 kt Min Pressure: 996 hPa Position: 19.6, 109.7 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: S (180°), 5.8 kt   |   Gust: 7.8 kt

Pressure: 30.01 steady   |   Air Temp: 85.1 °F

Water Temp: 86.9 °F   |   Dew Point: 77.7 °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.