🚨 Pratt, KS: Severe Thunderstorm Warning issued September 12 at 7:31PM CDT until September 12 at 8:15PM CDT by NWS Dodge City KS     🚨 Geary; Morris: Special Weather Statement issued September 12 at 7:31PM CDT by NWS Topeka KS     🚨 Flagler Beach to Volusia-Brevard County Line 0-20 nm; Volusia-Brevard County Line to Sebastian Inlet 0-20 nm: Marine Weather Statement issued September 12 at 8:31PM EDT by NWS Melbourne FL     🚨 Southeast Harford: Coastal Flood Advisory issued September 12 at 8:30PM EDT until September 13 at 2:00AM EDT by NWS Baltimore MD/Washington DC     🚨 Arlington/Falls Church/Alexandria: Coastal Flood Advisory issued September 12 at 8:30PM EDT until September 13 at 2:00AM EDT by NWS Baltimore MD/Washington DC     🚨 Neosho, KS: Severe Thunderstorm Warning issued September 12 at 7:28PM CDT until September 12 at 7:45PM CDT by NWS Wichita KS     🚨 Union, AR; Claiborne, LA; Union, LA: Severe Thunderstorm Warning issued September 12 at 7:28PM CDT until September 12 at 8:15PM CDT by NWS Shreveport LA     🚨 Fayette, PA; Greene, PA; Washington, PA; Westmoreland, PA; Monongalia, WV: Flood Warning issued September 12 at 8:27PM EDT until September 12 at 11:30PM EDT by NWS Pittsburgh PA     🚨 Morris; Lyon: Special Weather Statement issued September 12 at 7:27PM CDT by NWS Topeka KS     🚨 Bourbon, KS; Crawford, KS: Severe Thunderstorm Warning issued September 12 at 7:26PM CDT until September 12 at 7:45PM CDT by NWS Springfield MO    

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: 00 UTC 13 Sep 2026

Active storms summary

Select a Storm

NORBERT (EP142026)

Type: TS Max Wind: 45 kt Min Pressure: 1000 hPa Position: 17.8, -130.0 Basin: East Pacific
ZCZC MIATCDEP4 ALL TTAA00 KNHC DDHHMM Tropical Storm Norbert Discussion Number 13 NWS National Hurricane Center Miami FL EP142026 1100 AM HST Sat Sep 12 2026 A 1712 UTC ASCAT-B pass revealed that Norbert's center is located near the southern edge of a compact mass of deep convection, and the wind field is asymmetric, favoring the northern side. The scatterometer data showed peak wind vectors of 42 kt within the northwestern quadrant, and based on that data, the current intensity is lowered to 45 k. Norbert continues to move west-northwestward, or 285/10 kt, located to the south of the subtropical ridge extending westward from northern Mexico. The ridge is expected to keep Norbert on a west-northwestward to westward heading for the remainder of the forecast period. However, there has been another northward shift in the track model guidance, and the NHC official forecast has been moved in that direction using a blend of the previous forecast with the latest HCCA and GDMI aids, which lie along the northern boundary of the guidance envelope. The additional northward shift in Norbert's expected track will take it further into the zone of strong westerly shear that extends across much of the central Pacific basin, including over Hawaii. Little change in strength is expected during the next 24 hours while the shear still remains relatively low, but increasing shear and a marginal thermodynamic environment should cause additional weakening to begin on Sunday. In fact, the nearly all of the models respond to the hostile environment by showing Norbert dissipating into a trough of low pressure several hundred miles east-southeast of Hawaii potentially as early as Wednesday. For this update, the NHC forecast shows Norbert degenerating into a remnant low by Wednesday and dissipating by Thursday before reaching the longitude of the Hawaiian Islands. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 17.6N 129.6W 45 KT 50 MPH 12H 13/0600Z 18.0N 131.1W 45 KT 50 MPH 24H 13/1800Z 18.5N 133.2W 45 KT 50 MPH 36H 14/0600Z 18.8N 135.4W 40 KT 45 MPH 48H 14/1800Z 19.1N 138.0W 35 KT 40 MPH 60H 15/0600Z 19.3N 140.7W 35 KT 40 MPH 72H 15/1800Z 19.3N 143.4W 30 KT 35 MPH 96H 16/1800Z 18.5N 149.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 17/1800Z...DISSIPATED $$ Forecaster Berg NNNN

97E (EP972026)

Type: LO Max Wind: 25 kt Min Pressure: 1008 hPa Position: 17.2, -114.9 Basin: East Pacific
2-Day Formation: 80% (High) 5-Day Formation: N/A (N/A)

98W (WP982026)

Type: TD Max Wind: 20 kt Min Pressure: 1006 hPa Position: 17.1, 108.5 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: ENE (60°), 3.9 kt   |   Gust: 5.8 kt

Pressure: 29.96 falling   |   Air Temp: 88.2 °F

Water Temp: 89.4 °F   |   Dew Point: 80.1 °F

Swell: 1.0 ft   |   Wind Wave: 0.3 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.

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.