Catherine's Tropical Cyclone Watch

🚨 Grand Portage to Grand Marais MN; Grand Marais to Taconite Harbor MN; Taconite Harbor to Silver Bay Harbor MN: Dense Fog Advisory issued July 11 at 6:28AM CDT until July 11 at 10:00AM CDT by NWS Duluth MN 🚨 Bristol Bay greater than 15 NM: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 11 at 5:00PM AKDT by NWS Anchorage AK 🚨 Nikolski to Seguam Bering Side from 15 to 85 NM: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 12 at 5:00AM AKDT by NWS Anchorage AK 🚨 Unalga Pass to Nikolski Bering Side out to 15 NM: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 12 at 5:00AM AKDT by NWS Anchorage AK 🚨 Kuskokwim Delta from 15 to 80 NM: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 12 at 5:00AM AKDT by NWS Anchorage AK 🚨 North and West of Nunivak Island: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 11 at 5:00PM AKDT by NWS Anchorage AK 🚨 Adak to Kiska Bering Side: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 11 at 5:00PM AKDT by NWS Anchorage AK 🚨 Bristol Bay from Port Heiden to Cape Chichagof out to 15 NM: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 11 at 5:00PM AKDT by NWS Anchorage AK 🚨 Unalga Pass to Nikolski Pacific Side from 15 to 85 NM: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 12 at 5:00AM AKDT by NWS Anchorage AK 🚨 Unimak Pass: Small Craft Advisory issued July 11 at 3:28AM AKDT until July 12 at 5:00AM AKDT by NWS Anchorage AK

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 11 Jul 2026

Select a Storm

90C (CP902026)

Type: DB Max Wind: 25 kt Min Pressure: 1010 hPa Position: 12.5, -156.2 Basin: East Pacific

BAVI (WP092026)

Type: HU Max Wind: 80 kt Min Pressure: 950 hPa Position: 26.6, 123.2 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 110900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (BAVI) WARNING NR 042// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 26.6N 123.2E INITIAL INTENSITY: 80 KTS GEOGRAPHIC REFERENCE: 247 NM WEST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 20 KTS SIGNIFICANT WAVE HEIGHT: 52 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: A LARGE, NEARLY STEADY-STATE TYPHOON (TY) IS RAPIDLY APPROACHING MAINLAND CHINA, WITH A FORWARD MOTION OF 20 KTS, AN INCREASE FROM 13 KTS FROM SIX HOURS AGO. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A COMPLEX, CONVECTIVE STRUCTURE, CHARACTERIZED BY MULTIPLE CONCENTRIC RINGS AND A FORMATIVE INNER CORE FEATURING A 15-NM WIDE EYE. MICROWAVE IMAGERY FROM AN 110442Z AMSR-2 36 GHZ PASS CONFIRMS THIS STRUCTURE, EVIDENCING A CENTER SURROUNDED BY PARTIALLY OPEN RINGS MEASURING APPROXIMATELY 75 NM AND 200 NM IN DIAMETER. DESPITE A SUPPORTIVE ENVIRONMENT OF LOW VERTICAL WIND SHEAR (VWS) AND WARM SEA SURFACE TEMPERATURES (SST), THE SYSTEM'S PERSISTENT STRUGGLE TO CONSOLIDATE ITS INNER CORE CAN BE LARGELY ATTRIBUTED TO THE ENERGY-DISPERSIVE NATURE OF THESE CONCENTRIC RINGS. OCEAN SURFACE WIND DATA FROM THE AMSR2 AND A 110428Z OSCAT-3 PASSES REVEAL AN ASYMMETRIC WIND FIELD, WHERE THE STRONGEST WINDS ARE LOCATED IN THE NORTHEAST QUADRANT NEAR THE SECONDARY OUTER BAND. THESE SENSORS ALSO CONFIRM THAT THE EXTENT OF THE WIND FIELD IS CONTRACTING AS THE SYSTEM MAKES ITS FINAL APPROACH TO MAINLAND CHINA. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON RADAR IMAGERY AND THE EYE FEATURE ON MSI. THE INITIAL INTENSITY IS HELD AT 80 KTS WITH MEDIUM CONFIDENCE, BASED ON A BLEND OF THE SUBJECTIVE DVORAK FIXES OF T4.5-5.0 AND THE UPPER RANGE OF OBJECTIVE ESTIMATES FROM CIMSS, WHICH SPANS FROM 53 KTS TO 93 KTS. INITIAL WIND RADII BASIS: SCATTEROMETER DATA CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED SOUTH OF HONSHU AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.5 - 77 KTS RJTD: T5.0 - 90 KTS RCTP: T4.5 - 77 KTS KNES: T5.5 - 102 KTS CIMSS SATCON: 84 KTS AT 110630Z CIMSS ADT: 53 KTS AT 110540Z CIMSS AIDT: 62 KTS AT 110540Z CIMSS D-MINT: 82 KTS AT 110510Z CIMSS D-PRINT: 75 KTS AT 110540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 27-29 CELSIUS OUTFLOW: MODERATE RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TY 09W (BAVI) WILL MAINTAIN A NORTHWESTWARD TRAJECTORY UNDER THE STEERING INFLUENCE OF THE STR NEAR HONSHU THROUGH TAU 24, MAKING LANDFALL BETWEEN THE NEIGHBORING CITIES OF WENZHOU AND TAIZHOU, CHINA. BY TAU 36 AND TAU 48, THE CIRCULATION WILL TRACK NEAR THE YANGTZE RIVER DELTA AND EXECUTE A POLEWARD TURN AS IT CROSSES THE LOW- TO MID-LEVEL RIDGE AXIS. THE STORM HAS LESS THAN 12 HOURS REMAINING OVER WARM SST. GIVEN THE SYSTEM'S COMPLEX CONVECTIVE STRUCTURE AND MASSIVE SPATIAL EXTENT, THE INTENSITY WILL CHANGE VERY LITTLE PRIOR TO CROSSING THE COAST. LANDFALL WILL OCCUR PRIOR TO TAU 12, WHICH WILL INITIATE A RAPID WEAKENING TREND. THE LAND WILL EFFECTIVELY CUT OFF THE CORE FROM ITS PRIMARY ENERGY SOURCE AND FRICTIONALLY DISRUPT THE VORTEX. CONSEQUENTLY, THE TROPICAL CIRCULATION WILL DISSIPATE BY TAU 48. BECAUSE THE WIND FIELD IS SO EXTENSIVE, A FETCH OF ELEVATED WINDS WILL PERSIST ALONG THE COASTLINE OF CENTRAL CHINA AND PUSH NORTHWARD INTO THE YELLOW SEA WELL AFTER THE CIRCULATION CENTER HAS MOVED FAR INLAND. MODEL DISCUSSION: THE GUIDANCE ENVELOPE IS VERY TIGHT THROUGH TAU 48, MEASURING LESS THAN 20 NM ACROSS AT THE POINT OF LANDFALL. THE PRE…

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.

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.

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: SSE (160°), 9.7 kt | Gust: 11.7 kt

Pressure: 30.03 rising | Air Temp: 85.6 °F

Water Temp: 85.8 °F | Dew Point: 80.1 °F

Swell: 1.3 ft | Wind Wave: 1.6 ft

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.

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.

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.

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

CJ · TC