🚨 East Glacier Park Region: Winter Weather Advisory issued October 28 at 11:31PM MDT until October 29 at 6:00AM MDT by NWS Great Falls MT 🚨 Montgomery: None 🚨 Oahu in Honolulu, HI: Flood Advisory issued October 28 at 7:23PM HST until October 28 at 9:30PM HST by NWS Honolulu HI 🚨 Southern Hancock: Coastal Flood Advisory issued October 29 at 12:02AM CDT until October 29 at 4:00AM CDT by NWS New Orleans LA 🚨 Southern Hancock: Coastal Flood Advisory issued October 29 at 12:02AM CDT until October 30 at 5:00AM CDT by NWS New Orleans LA 🚨 Tinian; Saipan: High Surf Warning issued October 29 at 3:00PM ChST until October 30 at 4:00PM ChST by NWS Tiyan GU 🚨 Tinian; Saipan: High Surf Advisory issued October 29 at 3:00PM ChST until October 31 at 4:00PM ChST by NWS Tiyan GU 🚨 Guam; Rota: Rip Current Statement issued October 29 at 3:00PM ChST until October 31 at 4:00PM ChST by NWS Tiyan GU 🚨 Tinian; Saipan: Rip Current Statement issued October 29 at 3:00PM ChST until October 31 at 4:00PM ChST by NWS Tiyan GU 🚨 Tinian; Saipan: Coastal Flood Statement issued October 29 at 3:00PM ChST until October 30 at 4:00PM ChST by NWS Tiyan GU
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 MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
Tropical Depression Vance Discussion Number 31
NWS National Hurricane Center Miami FL EP222026
800 PM MST Wed Oct 28 2026
As anticipated, Vance's deep convection has re-ignited this evening,
with cloud top temperatures as cold as -80 degrees C. This
convective activity has pulled at the storm's center of circulation
as well, with earlier visible satellite imagery showing the center
briefly becoming obscured. TAFB's subjective Dvorak intensity
estimate remains at a 2.0 for a final T number, with objective
estimates from UW-CIMSS ranging from 27-36 kt. Based on these data,
Vance's initial intensity is held steady at 30 kt, though its
possible higher gusts could be present within the deep convection.
With this convective redevelopment, Vance has turned to the
north-northeast with a somewhat faster forward motion, estimated at
025/11 kt. Vance is being steered by a broad trough centered over
the eastern Pacific, and is expected to turn back to the north once
convection wanes on Thursday. The latest NHC track forecast reflects
largely a blend of the HCCA and TVCN models, and is a little east of
the previous track, partially due to adjustments in the initial
position.
Strong vertical wind shear will continue to erode Vance's core over
the next 24 hours. Simulated satellite imagery from the GFS and
ECMWF suggests that the ongoing convection, expected to last most of
overnight, will be Vance's last gasp before it is fully sheared off,
leading to the cyclone becoming a post-tropical remnant low during
the latter half of tomorrow. Vance is then expected to dissipate
shortly thereafter as it interacts with mountainous terrain along
the western Mexican coastline. The latest NHC intensity forecast
depicts slight weakening after Vance's convective max tonight,
before weakening into a post-tropical remnant low by tomorrow
evening.
Key Message:
1. Periods of heavy rainfall associated with Vance will impact
portions of western Mexico during much of this week. This rainfall
may produce flooding and mudslides across central and southern
Sinaloa, far southwestern Durango, and far northwestern Nayarit,
especially in areas along steep terrain.
FORECAST POSITIONS AND MAX WINDS
INIT 29/0300Z 21.1N 108.1W 30 KT 35 MPH
12H 29/1200Z 22.2N 107.6W 30 KT 35 MPH
24H 30/0000Z 23.7N 107.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 30/1200Z 25.2N 108.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 31/0000Z...DISSIPATED
$$
Forecaster Evans/Papin
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 290300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 30W (IN-FA) WARNING NR 023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 15.9N 154.6E
INITIAL INTENSITY: 115 KTS
GEOGRAPHIC REFERENCE: 493 NM NORTH OF OROLUK
MOVEMENT PAST 6 HOURS: WESTWARD AT 16 KTS
SIGNIFICANT WAVE HEIGHT: 53 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A STILL
QUASI-ANNULAR STRUCTURE WITH LIMITED BANDING OUTSIDE THE CENTRAL
DENSE OVERCAST, WITH A LARGE CLEAR EYE MAINTAINING APPROXIMATELY 40
NM DIAMETER. THE INNER CORE WAS CLEARLY DISRUPTED OVER THE LAST 12
HOURS BY LIGHT TO MODERATE NORTHEASTERLY VERTICAL SHEAR, WHICH
CAUSED PERIODIC BREAKS IN THE CONVECTIVE RING IN THE NORTHEAST
QUADRANT AND WEST-SKEWED CONVECTIVE ASYMMETRY. DEEP CONVECTION HAS
SINCE ROTATED BACK INTO THE UPSHEAR QUADRANTS, POTENTIALLY
BEGINNING TO REESTABLISH A MORE SYMMETRIC CORE STRUCTURE. THE
INITIAL INTENSITY IS SET AT 115 KT BASED ON A BLEND OF AGENCY
DVORAK INTENSITY ESTIMATES AND AUTOMATED INTENSITY ESTIMATES, WHICH
GENERALLY FELL OVER THE PAST SIX HOURS.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T6.0 - 115 KTS
RJTD: T6.5 - 127 KTS
RCTP: T5.5 - 102 KTS
CIMSS ADT: 99 KTS AT 282330Z
CIMSS AIDT: 102 KTS AT 282330Z
CIMSS D-MINT: 118 KTS AT 282306Z
CIMSS D-PRINT: 124 KTS AT 290000Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 10-15 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG EQUATORWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TYPHOON 30W (IN-FA) CONTINUES TO TRACK ON A
12-HOUR HEADING OF ABOUT 280 DEGREES ALONG THE SOUTHWESTERN
PERIPHERY OF A SUBTROPICAL RIDGE TO THE NORTHEAST. THIS GENERAL
MOTION IS EXPECTED TO CARRY IN-FA THROUGH THE NORTHERN MARIANA
ISLANDS IN 24 TO 36 HOURS. THE STORM'S INNER CORE APPEARS TO BE
UNDERGOING FLUCTUATIONS IN SYMMETRY AND OVERALL HEALTH AS IT FIGHTS
OFF LIGHT TO MODERATE NORTHEASTERLY VERTICAL SHEAR, WHICH HAS
CAUSED SOME SHORT-TERM WEAKENING. THE INTENSITY MAY CONTINUE TO
VACILLATE OVER THE SHORT TERM DUE TO INTERNAL VORTEX PROCESSES AS
THE STORM REMAINS WITHIN A GENERALLY FAVORABLE ENVIRONMENT. THE
CURRENT DOSE OF VERTICAL SHEAR IS EXPECTED TO DECREASE AFTER ABOUT
24 HOURS. THE JTWC FORECAST HOLDS THE INTENSITY STEADY FOR THE
FIRST 48 HOURS, AVERAGING THROUGH POTENTIAL FLUCTUATIONS. AFTER 48
HOURS, THE PASSAGE OF A LONGWAVE TROUGH OVER JAPAN WILL OPEN A
BREAK IN THE SUBTROPICAL RIDGE, DRAWING 30W NORTHWESTWARD OR
NORTHWARD DURING THE 48 TO 72 HOUR PERIOD. HOWEVER, THE OPENING IS
EXPECTED TO CLOSE QUICKLY AS THE TROUGH EXITS EASTWARD, USHERING IN
A NEW SUBTROPICAL RIDGE BEHIND IT TO THE NORTHWEST OF THE STORM,
BLOCKING ITS NORTHWARD PROGRESS. AN ABRUPT PIVOT BACK WESTWARD TO
THE SOUTH OF IWO TO IS FORECAST BY MOST DYNAMICAL AND AI-BASED
MODELS AFTER TAU 72, POTENTIALLY FOLLOWING A CLOCKWISE-SHAPED LOOP
IN THE TRACK. UNCERTAINTY IN BOTH TRACK AND INTENSITY GROWS DURING
AND AFTER THIS PIVOT DUE TO THE COMPLEX STEERING CURRENTS. THE
TYPHOON'S INTENSITY DURING THIS PERIOD WILL LIKELY BE GOVERNED
PRIMARILY BY OCEAN CONDITIONS, AS THE STORM'S SLOWING MOTION DURING
THE 48 TO 72 HOUR PERIOD MAY INDUCE COLD UPWELLING BENEATH THE
CIRCULATION, SUCH AS DEPICTED IN THE HAFS-A COUPLED MODEL. THE
MAGNITUDE OF THIS POTENTIAL COOLING IS UNCERTAIN, AS 30W WILL BE
TRACKING NEAR A TIGHT GRADIENT IN OCEAN HEAT CONTENT VALUES AROUND
THAT TIME. THE JTWC FORECAST SHOWS MODEST WEAKENING DURING TAU 48
TO 72. THEREAFTER, MODELS DISAGREE ON WHETH…
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: NE (40°), 17.5 kt | Gust: 21.4 kt
Pressure: 30.05 | Air Temp: 78.8 °F
Water Temp: 81.0 °F | Dew Point: 72.1 °F
Swell: 3.6 ft | Wind Wave: 4.6 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.
