🚨 Montgomery: None 🚨 Jewell, KS; Smith, KS: Severe Thunderstorm Warning issued August 22 at 6:27AM CDT until August 22 at 6:45AM CDT by NWS Hastings NE 🚨 Cleveland, OK; McClain, OK; Pontotoc, OK; Pottawatomie, OK: Severe Thunderstorm Warning issued August 22 at 6:27AM CDT until August 22 at 7:00AM CDT by NWS Norman OK 🚨 Cleveland; Pottawatomie: Special Weather Statement issued August 22 at 6:25AM CDT by NWS Norman OK 🚨 Fairfield, OH; Licking, OH: Flood Warning issued August 22 at 7:20AM EDT until August 22 at 2:00PM EDT by NWS Wilmington OH 🚨 Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley: Red Flag Warning issued August 22 at 4:16AM PDT until August 22 at 9:00PM PDT by NWS Medford OR 🚨 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 22 at 4:16AM PDT until August 22 at 9:00PM PDT by NWS Medford OR 🚨 Ashley; Chicot; Morehouse; West Carroll; East Carroll; Richland; Madison; Franklin; Catahoula; Tensas; Concordia; Bolivar; Sunflower; Leflore; Washington; Humphreys; Holmes; Issaquena; Sharkey; Yazoo; Madison; Warren; Hinds; Rankin; Claiborne; Copiah; Simpson; Jefferson; Adams; Franklin; Lincoln; Lawrence; Jefferson Davis; Marion: Heat Advisory issued August 22 at 6:14AM CDT until August 22 at 8:00PM CDT by NWS Jackson MS 🚨 Gulf of Alaska South of 57 Degrees North and East of 144 W: Small Craft Advisory issued August 22 at 3:05AM AKDT until August 23 at 5:00AM AKDT by NWS Juneau AK 🚨 Northern Lynn Canal: Small Craft Advisory issued August 22 at 3:04AM AKDT until August 22 at 4:00PM AKDT by NWS Juneau 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.
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 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 17W (SAUDEL) WARNING NR 016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 18.6N 145.8E
INITIAL INTENSITY: 95 KTS
GEOGRAPHIC REFERENCE: 204 NM NORTH OF SAIPAN
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 34 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TYPHOON 17W
(SAUDEL) WITH A QUICKLY DEVELOPING 20 NM EYE. THERE IS A WEAKNESS
WITHIN THE NORTHEASTERN PORTION OF THE EYEWALL, LIKELY DUE TO THE
WEDGE OF DRY AIR INTRUDING INTO THE VORTEX ABOUT 6 HOURS AGO. THE
SYSTEM HAS BEEN ANALYZED TO HAVE NOW UNDERGONE RAPID INTENSIFICATION,
STRENGTHENING FROM 60 KTS 24 HOURS AGO TO 95 KTS NOW. A 220617Z F18
SSMIS 91 GHZ MICROWAVE IMAGE REVEALED A DEFINED BAND OF DEEP
CONVECTION NEARLY ENTIRELY SURROUNDING THE CENTER WITH AN OUTER BAND
WRAPPING AROUND THE WESTERN PERIPHERY. THE 37 GHZ VERSION OF THE SAME
SSMIS PASS SHOWED A SYMMETRICAL MICROWAVE EYE FEATURE AT THE LOWER
LEVELS THAT NOW STACKS VERTICALLY WITH HEIGHT. THE TIMELY SSMIS PASS
LENDS HIGH CONFIDENCE TO THE INITIAL POSITION. THE INITIAL INTENSITY
OF 95 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED PRIMARILY ON THE
AGENCY DVORAK ESTIMATES OF T5.0-5.5. THE CIMSS ADT ESTIMATE IS
CURRENTLY TOO LOW DUE TO THE RAPID DEVELOPMENT OF THE EYE AND
CONSTRAINTS ON THE CI OUTPUT. ENVIRONMENTAL ANALYSIS INDICATES THAT
17W IS NOW IN A HIGHLY FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG
POLEWARD OUTFLOW ALOFT, LOW (5-10 KTS) VERTICAL WIND SHEAR, AND VERY
WARM (30-31 C) SEA SURFACE TEMPERATURES.
INITIAL WIND RADII BASIS: 212336Z METOP-C ASCAT SCATTEROMETER DATA
AND OBJECTIVE BEST TRACK
CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A SUBTROPICAL
RIDGE (STR) POSITIONED TO THE NORTHEAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T5.5 - 102 KTS
RJTD: T4.5 - 77 KTS
RCTP: T5.0 - 90 KTS
KNES: T5.5 - 102 KTS
CIMSS ADT: 59 KTS AT 220600Z
CIMSS AIDT: 67 KTS AT 220600Z
CIMSS D-MINT: 93 KTS AT 220616Z
CIMSS D-PRINT: 83 KTS AT 220600Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
VWS: 5-10 KTS
SST: 30-31 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
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: TY 17W IS FORECAST TO TRACK WEST-NORTHWESTWARD
ALONG THE SOUTHWESTERN PERIPHERY OF THE SOUTHWESTERN PERIPHERY OF
THE SUBTROPICAL RIDGE TO THE NORTHEAST THROUGH TAU 48. NEAR TAU 48,
THE STR IS EXPECTED TO MERGE WITH ANOTHER STR POSITIONED OVER SOUTHERN
JAPAN. THE COMBINED STEERING INFLUENCE OF THE RIDGING COMPLEX WILL
KEEP 17W ON A WEST-NORTHWESTWARD TRAJECTORY THROUGH TAU 96. LANDFALL
OVER OKINAWA IS CURRENTLY FORECAST TO OCCUR JUST BEFORE TAU 96.
AFTERWARD, TRACK SPEEDS ARE EXPECTED TO SLOW THROUGH TAU 120 AS THE
PRIMARY STEERING MECHANISM TRANSITIONS TO A SUBTROPICAL RIDGE
POSITIONED OVER EASTERN CHINA. IN TERMS OF INTENSITY, 17W IS FORECAST
TO CONTINUE INTENSIFYING THROUGH TAU 36 TO A PEAK OF AROUND 130 KTS AS
THE ENVIRONMENT REMAINS HIGHLY CONDUCIVE. AFTER TAU 36, THE POLEWARD
OUTFLOW CHANNEL WILL WEAKEN AND NORTHERLY SHEAR WILL BEGIN TO
INCREASE, CAUSING 17W TO START ON A WEAKENING TREND AS IT APPROACHES
OKINAWA. THE LANDFALL INTENSITY IS FORECAST TO BE ABOUT 90 KTS AS IT
PASSES OVER THE ISLAND. FURTHER WEAKENING THROUGH TAU 120 IS EXPECTED
DUE TO GREATLY INCREASING NORTHERLY SHEAR CAUSED BY THE STRONG RIDGE
OVER EASTERN CHINA.
MODEL DISCUSSION: MODEL TRACK GUIDANCE IS IN GOOD AGREEMENT THROUGH
TAU 72 BESIDES TWO MINOR OUTLIERS IN NAVGEM AND JGSM, WHICH MAKE UP
THE SOUTHERNMO…
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.
WDPN32 PGTW 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 18W (NARRA) WARNING
NR 007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 21.1N 108.1E
INITIAL INTENSITY: 30 KTS
GEOGRAPHIC REFERENCE: 123 NM EAST OF HANOI, VIETNAM
MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 01 KTS
SIGNIFICANT WAVE HEIGHT: 12 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
DEPRESSION 18W (NARRA) WITH AN ELONGATED PARTIALLY-EXPOSED
LOW-LEVEL CIRCULATION CENTER (LLCC) JUST OFF THE COAST OF NORTHERN
VIETNAM. BURSTS OF CONVECTION HAVE BEEN FORMING ALONG THE COAST OVER
THE PAST 4 HOURS, WEST OF THE ASSESSED CENTER. A 220257Z METOP-C ASCAT
SCATTEROMETER PASS REVEALED THE POORLY-DEFINED CIRCULATION WITH A
LARGE SWATH OF 25-30 KTS ALONG THE SOUTHERN SEMICIRCLE. THE INITIAL
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE RAGGED LLCC IN
ANIMATED RADAR IMAGERY AND MSI. THE INITIAL INTENSITY OF 30 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED PRIMARILY ON THE AFOREMENTIONED
ASCAT PASS. ENVIRONMENTAL ANALYSIS INDICATES THAT 18W IS IN A MARGINAL
ENVIRONMENT CHARACTERIZED BY WEAK EQUATORWARD OUTFLOW ALOFT, LOW TO
MODERATE (15-20 KTS) NORTHEASTERLY SHEAR, AND VERY WARM (30-31 C) SEA
SURFACE TEMPERATURES.
INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).
CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT WITH A
NEAR EQUATORIAL RIDGE (NER) TO THE SOUTH AND A SUBTROPICAL RIDGE
(STR) TO THE NORTHWEST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.0 - 30 KTS
RCTP: T1.5 - 25 KTS
KNES: T3.0 - 45 KTS
CIMSS ADT: 47 KTS AT 220540Z
CIMSS AIDT: 41 KTS AT 220540Z
CIMSS D-MINT: 31 KTS AT 220618Z
CIMSS D-PRINT: 33 KTS AT 220540Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 15-20 KTS
SST: 30-31 CELSIUS
OUTFLOW: WEAK EQUATORWARD
OTHER FACTORS: DRY AIR ENTRAINMENT FROM THE SOUTH
ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: NOT APPLICABLE
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: 18W IS FORECAST TO MAKE A SLOW COUNTERCLOCKWISE
LOOP OVER THE NEXT 72 HOURS AS THE SYSTEM REMAINS PLACED WITHIN A
COMPETING STEERING PATTERN WITH RIDGING TO BOTH THE NORTH AND SOUTH.
HOWEVER, THE ACTUAL TRACK OF 18W IS LIKELY TO BE HIGHLY ERRATIC DURING
THIS TIME. AFTER TAU 72, 18W IS FORECAST TO BE DRIVEN NORTHWARD INTO
SOUTHERN CHINA UNDER THE INFLUENCE OF THE LOW-LEVEL FLOW. THE
ENVIRONMENT IS EXPECTED TO REMAIN MARGINAL WITH MODERATE NORTHEASTERLY
SHEAR CONTINUING TO IMPACT THE VORTEX WITH DRY AIR ENTRAINMENT FROM
THE SOUTH. THESE FACTORS ARE OFFSET BY THE VERY WARM WATERS WITHIN THE
GULF OF TONKIN. SOME MODELS, SUCH AS ECMWF, DO SHOW THE NORTHEASTERLY
SHEAR DECREASING AND THE SYSTEM REMAINING QUASISTATIONARY OVER THE
GULF OF TONKIN. IF THIS SCENARIO OCCURS, THEN FURTHER INTENSIFICATION
COULD BE POSSIBLE. AS IT STANDS, THE JTWC FORECAST CALLS FOR A STEADY
INTENSITY THROUGH TAU 60 BEFORE WEAKENING AS THE VORTEX TRACKS INTO
SOUTHERN CHINA WITH DISSIPATION AT TAU 96.
MODEL DISCUSSION: MODEL TRACK GUIDANCE CONTINUES TO BE IN VERY POOR
AGREEMENT, BUT IT GENERALLY SHOWS A SOUTHWARD TURN THROUGH TAU 48
FOLLOWED BY A TURN BACK TO THE NORTH. GFS SHOWS A TRACK THAT SKIRTS
THE COAST OF VIETNAM, AND THEREFORE WASHES OUT THE CIRCULATION AT
AROUND TAU 48. THE JTWC TRACK FORECAST IS PLACED NEAR THE MULTI-MODEL
CONSENSUS WITH VERY LOW CONFIDENCE. INTENSITY GUIDANCE IS ALSO IN POOR
AGREEMENT DUE TO DIFFERING AMOUNTS OF LAND INTERACTION. THE JTWC
INTENSITY FORECAST IS PLACED NEAR THE HAFS-A THROUGHOUT THE FORECAST
PERIOD WITH LOW CO…
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: SW (230°), 7.8 kt | Gust: 9.7 kt
Pressure: 30.01 steady | Air Temp: 85.1 °F
Water Temp: 87.1 °F | Dew Point: 79.7 °F
Swell: 0.7 ft | Wind Wave: 0.7 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.
