🚨 Modoc County Except for the Surprise Valley; Klamath Basin and the Fremont-Winema National Forest; South Central Oregon Desert including the BLM Land in Eastern Lake and Western Harney Counties: Fire Weather Watch issued August 25 at 5:32PM PDT until August 27 at 8:00PM PDT by NWS Medford OR 🚨 Modoc County Except for the Surprise Valley; Klamath Basin and the Fremont-Winema National Forest; South Central Oregon Desert including the BLM Land in Eastern Lake and Western Harney Counties: Red Flag Warning issued August 25 at 5:32PM PDT until August 26 at 8:00PM PDT by NWS Medford OR 🚨 Beaver, OK; Texas, OK; Carson, TX; Hansford, TX; Hutchinson, TX; Moore, TX; Ochiltree, TX; Potter, TX; Randall, TX; Roberts, TX; Sherman, TX: Severe Thunderstorm Warning issued August 25 at 7:32PM CDT until August 25 at 8:30PM CDT by NWS Amarillo TX 🚨 Morrill, NE: Severe Thunderstorm Warning issued August 25 at 6:31PM MDT until August 25 at 7:15PM MDT by NWS Cheyenne WY 🚨 Bent, CO; Otero, CO: Severe Thunderstorm Warning issued August 25 at 6:31PM MDT until August 25 at 7:00PM MDT by NWS Pueblo CO 🚨 Northern Brevard Barrier Islands: Special Weather Statement issued August 25 at 8:29PM EDT by NWS Melbourne FL 🚨 St. Martin, LA; St. Mary, LA: Severe Thunderstorm Warning issued August 25 at 7:29PM CDT until August 25 at 7:45PM CDT by NWS Lake Charles LA 🚨 Montgomery: None 🚨 Banner, NE; Kimball, NE; Goshen, WY; Laramie, WY: Severe Thunderstorm Warning issued August 25 at 6:26PM MDT until August 25 at 7:00PM MDT by NWS Cheyenne WY 🚨 Cheyenne, NE: Severe Thunderstorm Warning issued August 25 at 6:25PM MDT until August 25 at 7:15PM MDT by NWS Cheyenne WY
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.
ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM
Tropical Storm Iselle Discussion Number 10
NWS National Hurricane Center Miami FL EP092026
200 PM PDT Tue Aug 25 2026
The structure of Iselle has significantly degraded during the past
several hours, with the low-level circulation further detaching
from the mid-level center located well to the northeast. This
change has caused any deep convection to be located well away from
the center near the old mid-level center and is representative of
a weakening cyclone. A recent ASCAT scatterometer pass showed peak
winds of about 45 kt, so the initial intensity is set to 50 kt,
consistent with the low bias of the instrument.
Further weakening is anticipated due to continued shear,
progressively cooler water and dry air entrainment near the core of
the cyclone. Perhaps because of the poor initial structure,
Iselle isn't expected to be a particularly resilient cyclone, and
no model shows organized deep convection beyond 36 hours. The new
NHC intensity forecast is lower than the last one, keeping the same
general rate of weakening, but it shows a much earlier transition
into a remnant low.
Satellite fixes show that the storm continues to move to the
west-northwest, and little change in track is anticipated for the
next couple of days due to ridging extending from the southern
United States. As the storm weakens, it should turn more westward
by Thursday due to the cyclone becoming steered more by the
low-level flow. The guidance is shifting southward, consistent
with a decaying system, so the new forecast is shifted equatorward,
closest to the Google DeepMind ensemble mean.
FORECAST POSITIONS AND MAX WINDS
INIT 25/2100Z 21.0N 121.8W 50 KT 60 MPH
12H 26/0600Z 21.3N 123.0W 40 KT 45 MPH
24H 26/1800Z 21.8N 124.7W 35 KT 40 MPH
36H 27/0600Z 22.4N 126.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 27/1800Z 23.0N 128.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 28/0600Z 23.5N 130.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 28/1800Z...DISSIPATED
$$
Forecaster Blake/Evans
NNNN
ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM
Remnants Of Julio Discussion Number 5
NWS National Hurricane Center Miami FL EP102026
200 PM PDT Tue Aug 25 2026
Satellite and microwave data indicate that the circulation of Julio
has opened up into a trough of low pressure. Thus, it is no
longer a tropical cyclone, and this is the last NHC advisory. The
initial wind speed is set to 40 kt, consistent with the ASCAT-B pass
from a few hours ago. The remnant vorticity should wrap into the
circulation of Tropical Storm Iselle and totally lose any identity
soon.
For additional information on the remnants please see High Seas
Forecasts issued by the National Weather Service, under AWIPS
header NFDHSFEPI, WMO header FZPN01 KWBC, and on the web at
ocean.weather.gov/shtml/NFDHSFEPI.php
FORECAST POSITIONS AND MAX WINDS
INIT 25/2100Z 21.0N 119.5W 40 KT 45 MPH...REMNANTS OF
12H 26/0600Z...DISSIPATED
$$
Forecaster Blake/Evans
NNNN
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 252100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 17W (SAUDEL) WARNING NR 030//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 27.5N 128.1E
INITIAL INTENSITY: 80 KTS
GEOGRAPHIC REFERENCE: 62 NM NORTH-NORTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 45 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TYPHOON
(TY) 17W (SAUDEL) AS A DEGRADING SYSTEM WITH A RECENTLY FORMED
EXPANSIVE DRY SLOT WRAPPING INTO THE CORE FROM THE SOUTHERN
SEMICIRCLE. A RAGGED EYE BRIEFLY REFORMED, BUT QUICKLY COLLAPSED AS
THE HIGH (25-30 KTS) VERTICAL WIND SHEAR (VWS) AND SUBSTANTIAL DRY
AIR ARE CLEARLY TAKING THEIR TOLL ON THE SYSTEM. THE 251625Z AMSR3
MICROWAVE DATA REVEALS A POORLY DEFINED MICROWAVE EYE FEATURE IN
THE LOWER LEVELS AND A BROAD UPPER LEVEL WITH THE BULK OF DEEP
CONVECTION CONFINED TO THE EASTERN QUADRANT. ENVIRONMENTAL ANALYSIS
REVEALS A MARGINAL ENVIRONMENT CHARACTERIZED BY HIGH VWS AND DRY
AIR ENTRAINMENT, OFFSET BY WARM (27-28 C) SEA SURFACE TEMPERATURES
(SST) AND DECENT RADIAL OUTFLOW. THE INITIAL POSITION IS PLACED
WITH HIGH CONFIDENCE BASED ON THE PINHOLE EYE THAT BRIEFLY FORMED
AND WAS VISIBLE IN ANIMATED EIR. THE INITIAL INTENSITY OF 80 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE CIMSS AUTOMATED
INTENSITY ESTIMATES AND AGENCY DVORAK FIXES LISTED BELOW.
INITIAL WIND RADII BASIS: ADJUSTED WIND RADII USING THE 251305Z
ASCAT UHR DATA
CURRENT STEERING MECHANISM: THE NORTHWESTWARD EXTENSION OF THE
SUBTROPICAL RIDGE CENTERED TO THE NORTHEAST OF THE SYSTEM
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.5 - 77 KTS
RJTD: T4.5 - 77 KTS
RCTP: T4.0 - 65 KTS
KNES: T5.0 - 90 KTS
CIMSS SATCON: 72 KTS AT 251830Z
CIMSS ADT: 59 KTS AT 251900Z
CIMSS AIDT: 60 KTS AT 251900Z
CIMSS D-MINT: 77 KTS AT 251748Z
CIMSS D-PRINT: 77 KTS AT 251830Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 25-30 KTS
SST: 27-28 CELSIUS
OUTFLOW: MODERATE RADIAL
OTHER FACTORS: DRY AIR ENTRAINMENT
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 17W IS FORECAST TO CONTINUE TRACKING
NORTHWESTWARD FOR THE NEXT 24 HOURS WHILE IT REMAINS UNDER THE
STEERING INFLUENCE OF THE STR CENTERED TO THE NORTHEAST OF THE
SYSTEM. AROUND TAU 12, 17W WILL ENCOUNTER A WEAKNESS IN THE
RIDGE EXTENSION AND SLOW ITS SPEED OF ADVANCE. SIMULTANEOUSLY, A
STR CENTERED OVER EASTERN CHINA WILL BUILD AND ASSUME STEERING
AUTHORITY OF 17W AT AROUND TAU 24 AND INDUCE A SOUTHWESTWARD TRACK
THROUGH TAU 96. WHILE THE STR BUILDS BETWEEN TAU 24-36, SAUDEL'S
TRACK SPEEDS WILL BE RELATIVELY SLOWER, BUT IT IS EXPECTED TO
ACCELERATE AS IT APPROACHES THE COAST AS THE STR STRENGTHENS AND
DRIVES 17W SOUTHWESTWARD. LANDFALL IS FORECAST TO OCCUR BETWEEN TAU
48-60 WITH DISSIPATED EXPECTED OVERLAND NO LATER THAN TAU 96.
REGARDING INTENSITY, 17W IS FORECAST TO GRADUALLY WEAKEN AS THE
ENVIRONMENT REMAINS CONSISTENT FOR THE NEXT 48 HOURS, DEFINED BY
MODERATE TO HIGH (20-30 KTS) VWS AND SIGNIFICANT DRY AIR
ENTRAINMENT, BUT THE STORM IS EXPECTED TO BE PARTIALLY SUSTAINED BY
THE FAVORABLE SSTS AND OUTFLOW. RAPID WEAKENING IS EXPECTED AFTER
LANDFALL WITH DISSIPATION ULTIMATELY OCCURRING BY TAU 96 DUE TO
TERRAIN INTERACTION.
MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT THROUGH LANDFALL, WITH GSM AND NAVGEM AS THE SOLE
EQUATORWARD OUTLIERS. POST-LANDFALL, THE GUIDANCE ENVELOPE OPENS AS
MODELS DISAGREE ON THE IMPACTS OF LAND INTERACTION. OVERALL, ALL
MODELS DEPICT THE STORM TRACKING SOUTHWESTWARD OVER MAIN…
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.
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.
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.
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: N (10°), 9.7 kt | Gust: 13.6 kt
Pressure: 29.99 | Air Temp: 85.3 °F
Water Temp: 87.3 °F | Dew Point: 78.8 °F
Swell: 0.7 ft | Wind Wave: 1.0 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.
