🚨 White Pine County; Southern Lander County and Southern Eureka County: Special Weather Statement issued August 28 at 5:32PM PDT by NWS Elko NV 🚨 McMullen: Special Weather Statement issued August 28 at 7:29PM CDT by NWS Corpus Christi TX 🚨 Logan County: Special Weather Statement issued August 28 at 6:28PM MDT by NWS Denver CO 🚨 Montgomery: None 🚨 Webb: Special Weather Statement issued August 28 at 7:27PM CDT by NWS Corpus Christi TX 🚨 Atkinson, GA; Bacon, GA; Coffee, GA; Ware, GA: Flash Flood Warning issued August 28 at 8:27PM EDT until August 28 at 11:30PM EDT by NWS Jacksonville FL 🚨 Colquitt, GA; Tift, GA: Flood Advisory issued August 28 at 8:26PM EDT until August 28 at 10:30PM EDT by NWS Tallahassee FL 🚨 Northwest Beaverhead County; Beaverhead and Western Madison below 6000ft; Gallatin and Madison County Mountains and Centennial Mountains: Special Weather Statement issued August 28 at 6:25PM MDT by NWS Great Falls MT 🚨 Wasatch Plateau/Book Cliffs; Central Mountains; Sanpete Valley: Special Weather Statement issued August 28 at 6:24PM MDT by NWS Salt Lake City UT 🚨 Hays; Comal; Guadalupe: Special Weather Statement issued August 28 at 7:24PM CDT by NWS Austin/San Antonio TX
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 MIATCDEP1 ALL
TTAA00 KNHC DDHHMM
Tropical Storm Karina Discussion Number 5
NWS National Hurricane Center Miami FL EP112026
200 PM PDT Fri Aug 28 2026
Karina is slowly becoming better organized, with visible satellite
imagery showing increased spiral banding around a central dense
overcast. The low-level center is still on the southwestern side of
the convection, but the distance is decreasing to the mid-level
center. A recent scatterometer pass shows maximum winds near 50
kt, and given the known low bias of ASCAT, the intensity is set to
55 kt, which also matches the latest TAFB classification.
Karina is moving northwestward at about 9 kt. There are no
changes in the synoptic pattern to report as a mid-level ridge
over the SW United States should gradually build westward. This
evolution forces Karina to turn west-northwestward and westward this
weekend. A bend back to the northwest is likely early next week
due to the ridge being weakened by an approaching mid-latitude
trough. The guidance envelope is very similar to the last forecast
advisory, and the new forecast is close to the previous one, near
the latest HFIP Corrected Consensus Approach (HCCA) model.
There is some increasing confidence that Karina will become a
strong hurricane with signs of inner-core alignment ongoing. Given
the light shear, it seems very likely that sometime this weekend
the low- and mid-level centers will become positioned for
significant strengthening in otherwise conducive large-scale
conditions. Thus the new forecast is higher than the last one, and
could be conservative near peak intensity given rising rapid
intensification probabilities from SHIPS and DTOPS. Weakening
should begin in 4 days or so due to the cyclone moving over the
cooling waters of the eastern Pacific.
FORECAST POSITIONS AND MAX WINDS
INIT 28/2100Z 13.7N 115.5W 55 KT 65 MPH
12H 29/0600Z 14.6N 116.6W 65 KT 75 MPH
24H 29/1800Z 15.9N 118.4W 75 KT 85 MPH
36H 30/0600Z 16.9N 120.1W 90 KT 105 MPH
48H 30/1800Z 17.5N 121.9W 100 KT 115 MPH
60H 31/0600Z 17.9N 123.4W 110 KT 125 MPH
72H 31/1800Z 18.2N 125.1W 110 KT 125 MPH
96H 01/1800Z 19.1N 128.1W 100 KT 115 MPH
120H 02/1800Z 20.0N 130.5W 80 KT 90 MPH
$$
Forecaster Blake
NNNN
ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
Tropical Storm Lowell Discussion Number 5
NWS National Hurricane Center Miami FL EP122026
1100 AM HST Fri Aug 28 2026
Lowell continues to be affected by easterly vertical shear. The
low-level center is currently exposed to the east of the main
convective mass, and satellite imagery is hinting that the
mid-level center is west or southwest of the low-level center. A
recent ASCAT overpass showed no tropical-storm force winds in the
eastern semicircle, but it did not sample the winds under the
deep convection. Satellite intensity estimates range from 30-45
kt, and the initial intensity is held at 40 kt.
Lowell is starting its forecast westward turn. The initial motion
is 305/4 kt, and the cyclone should start a westward motion within
the next 12 h. A general westward motion should continue for the
next 2-3 days as a low- to mid-level ridge to the north of Lowell
becomes the primary steering influence. The forecast uncertainty
becomes quite large by 120 h due to the possible effect of the
larger Tropical Storm Storm Karina on Lowell's steering currents.
The track guidance has a significant spread in Lowell's forward
speed between the faster HCCA/UKMET/Google DeepMind Ensemble Mean
and the slower ECMWF/Canadian/GFS. The new track forecast leans
towards the faster models, and it is a little south of the previous
forecast.
The current shear is expected to decrease in 18-24 hours. After
that time, conditions appear generally favorable for strengthening,
with the caveat that water vapor imagery shows mid- to upper-level
dry air not far north of the cyclone's forecast track. The
intensity forecast shows only modest strengthening during the next
24 h due to the shear and Lowell's current poor level of
organization. After that, a faster rate of development is likely,
particularly after 60 h. The intensity near the end of the forecast
period is dependent on how close Lowell is to Karina. The current
faster track forecast keeps the cyclones farther apart and thus
Lowell is forecast to continue strengthening. However, if the
slower track guidance is correct, Lowell could wind up in stronger
shear and with a lower intensity due to proximity to Karina.
FORECAST POSITIONS AND MAX WINDS
INIT 28/2100Z 12.5N 133.4W 40 KT 45 MPH
12H 29/0600Z 12.6N 134.0W 40 KT 45 MPH
24H 29/1800Z 12.8N 135.4W 45 KT 50 MPH
36H 30/0600Z 13.0N 136.9W 50 KT 60 MPH
48H 30/1800Z 13.1N 138.6W 55 KT 65 MPH
60H 31/0600Z 13.4N 140.5W 65 KT 75 MPH
72H 31/1800Z 13.6N 142.4W 75 KT 85 MPH
96H 01/1800Z 14.1N 145.6W 90 KT 105 MPH
120H 02/1800Z 14.7N 149.0W 95 KT 110 MPH
$$
Forecaster Beven
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.
WDPN33 PGTW 282100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (BANG-LANG) WARNING NR 011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 20.5N 167.0E
INITIAL INTENSITY: 65 KTS
GEOGRAPHIC REFERENCE: 75 NM NORTH-NORTHEAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 11 KTS
SIGNIFICANT WAVE HEIGHT: 23 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TYPHOON
(TY) 20W (BANG-LANG) WITH QUICKLY WARMING CLOUD TOPS AND COLLAPSING
DEEP CONVECTION WITHIN THE CENTRAL DENSE OVERCAST (CDO). FOR A
BRIEF MOMENT, IT APPEARED AS IF 20W WAS ATTEMPTING TO FORM AN EYE,
HOWEVER, THE CONVECTION WARMED AND THE ATTEMPT WAS ABANDONED. THE
281723Z SSMIS DATA REVEALS A VERY SLIGHT PATCH OF LOWER EMISSIVITY
IN THE CENTER OF THE CDO REGION, BUT IT REMAINS FAR FROM A DEFINED
MICROWAVE EYE. ENVIRONMENTAL ANALYSIS REVEALS A FAVORABLE
ENVIRONMENT, CHARACTERIZED BY LOW (10-15 KTS) VERTICAL WIND SHEAR
(VWS), WARM (29-30 C) SEA SURFACE TEMPERATURES (SST), GOOD OUTFLOW
ALOFT. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED
ON THE AFOREMENTIONED 281723Z SSMIS MICROWAVE DATA. THE INITIAL
INTENSITY OF 65 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE
AGENCY DVORAK FIXES AND CIMSS AUTOMATED INTENSITY ESTIMATES LISTED
BELOW, WITH A SLIGHT BIAS CORRECTION APPLIED TO THE INITIAL
INTENSITY. THE DVORAK FIXES ARE ASSESSED TO BE SLIGHTLY
UNDER-ESTIMATING THE INTENSITY DUE TO THE VERY COMPACT NATURE OF
THE STORM.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SOUTHWESTWARD EXTENSION OF A
SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.5 - 55 KTS
RJTD: T3.0 - 45 KTS
RCTP: T3.5 - 55 KTS
KNES: T3.5 - 55 KTS
PHFO: T3.5 - 55 KTS
CIMSS SATCON: 64 KTS AT 281910Z
CIMSS ADT: 63 KTS AT 281910Z
CIMSS AIDT: 53 KTS AT 281910Z
CIMSS D-MINT: 47 KTS AT 281722Z
CIMSS D-PRINT: 59 KTS AT 281830Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 10-15 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE RADIAL
ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TY 20W (BANG-LANG) IS FORECAST TO CONTINUE
TRACKING NORTH-NORTHEASTWARD WHILE IT REMAINS UNDER THE STEERING
INFLUENCE OF THE STR CENTERED TO ITS NORTHEAST FOR THE NEXT 24-36
HOURS. AROUND TAU 36, AN UPPER-LEVEL TROUGH IS EXPECTED TO PASS TO
THE NORTH AND WEAKEN THE RIDGE, INDUCING A NORTH-NORTHWESTWARD
TRACK MOTION FOR 20W THROUGH TAU 60. ALSO BEGINNING AROUND TAU 36,
20W IS EXPECTED TO BEGIN TO INTERACT WITH TROPICAL STORM (TS) 21W
(ETAU), REINFORCING THE NORTH-NORTHWEST TRACK MOTION. INTERACTION
WITH TS 21W MAY RESULT IN STORM MOTION NOT REFLECTED IN THE
OFFICIAL FORECAST, AS THE DEGREE OF INTERACTION IS STILL UNCERTAIN.
TY 20W IS EXPECTED TO BEGIN SUBTROPICAL TRANSITION (STT) AROUND TAU
60 AND COMPLETE TRANSITION NO LATER THAN TAU 72. BY TAU 72, 20W IS
FORECAST TO HAVE CROSSED THE 26C ISOTHERM AND BE EMBEDDED UNDER THE
UPPER-LEVEL TROUGH. REGARDING INTENSITY, 20W IS FORECAST TO
INTENSIFY THROUGH TAU 24 TO A PEAK OF 85 KTS AS THE ENVIRONMENT
REMAINS FAVORABLE. IF 20W IS ABLE TO SUCCESSFULLY FORM AN EYE, A
HIGHER PEAK INTENSITY IS POSSIBLE. STARTING AROUND TAU 36, SHEAR IS
EXPECTED TO INCREASE AS THE UPPER-LEVEL TROUGH PASSES AND OCEAN
HEAT CONTENT WILL RAPIDLY DROP AS THE SYSTEM PROGRESSES POLEWARD.
AS A RESULT, BANG-LANG IS FORECAST TO GRADUALLY WEAKEN FROM TAU
24-72. THE HIGHLY COMPACT NATURE OF THE SYSTEM MAY CAUSE THE
INTENSITY TO BE VOLATILE AS SMALL CHANGES IN THE ENVIRONMENT COULD
HAVE A LARGE IMPACT ON THE VORT…
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 282100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 21W (ETAU) WARNING NR
008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 26.2N 166.0E
INITIAL INTENSITY: 45 KTS
GEOGRAPHIC REFERENCE: 415 NM NORTH OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 11 KTS
SIGNIFICANT WAVE HEIGHT: 23 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
STORM (TS) 21W (ETAU) AS A FULLY EXPOSED AND COMPACT LOW-LEVEL
CIRCULATION CENTER (LLCC). THE PERSISTENT CONVECTION THAT HAD
PREVIOUSLY PARTIALLY OBSCURED THE LLCC HAS NOW BEEN SHEARED TO THE
EAST BY THE VERY STRONG WESTERLY VERTICAL WIND SHEAR (VWS). THE
281721 SSMIS MICROWAVE IMAGERY CONFIRMS 21W IS A VERY SHALLOW
SYSTEM, AND ALSO REVEALS ETAU'S LOW LEVEL CLOUD BANDS ARE FEEDING
INTO TYPHOON (TY) 20W TO THE SOUTH. ENVIRONMENTAL ANALYSIS REVEALS
A MARGINAL ENVIRONMENT, CHARACTERIZED BY HIGH (30-35 KTS) VWS, WARM
(27-28 C) SEA SURFACE TEMPERATURES (SST), GOOD POLEWARD OUTFLOW.
THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE
FULLY EXPOSED NATURE OF THE LLCC. THE INITIAL INTENSITY OF 45 KTS
IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AGENCY DVORAK FIXES
AND THE AUTOMATED CIMSS ESTIMATES LISTED BELOW.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: THE WESTERN PERIPHERY OF A SUBTROPICAL
RIDGE (STR) POSITIONED TO THE EAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.5 - 35 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.0 - 30 KTS
PHFO: T3.0 - 45 KTS
CIMSS SATCON: 40 KTS AT 281700Z
CIMSS ADT: 34 KTS AT 281940Z
CIMSS AIDT: 37 KTS AT 281940Z
CIMSS D-MINT: 34 KTS AT 281721Z
CIMSS D-PRINT: 35 KTS AT 281830Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 30-35 KTS
SST: 27-28 CELSIUS
OUTFLOW: MODERATE POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: LOW
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS 21W IS FORECAST TO CONTINUE TRACKING
NORTH-NORTHWESTWARD FOR THE NEXT 24 HOURS WHILE IT REMAINS UNDER
THE INFLUENCE OF THE STEERING STR CENTERED TO ITS EAST. AFTER ABOUT
TAU 24, 21W IS EXPECTED TO CURVE NORTH-NORTHEASTWARD AS AN
UPPER-LEVEL TROUGH BREAKS DOWN THE STEERING RIDGE. ADDITIONALLY,
21W IS EXPECTED TO BEGIN INTERACTING WITH TY 20W AROUND TAU 36,
WHICH WILL FURTHER REINFORCE THE NORTHEASTWARD TRACK THROUGH TAU
72. INTERACTION WITH TS 21W MAY RESULT IN STORM MOTION NOT
REFLECTED IN THE OFFICIAL FORECAST, AS THE DEGREE OF INTERACTION IS
STILL UNCERTAIN. TS 21W IS EXPECTED TO BEGIN SUBTROPICAL TRANSITION
(STT) AROUND TAU 60 AND COMPLETE TRANSITION NO LATER THAN TAU 72.
BY TAU 72, 21W IS FORECAST TO HAVE CROSSED THE 26C ISOTHERM AND BE
EMBEDDED UNDER THE UPPER-LEVEL TROUGH. REGARDING INTENSITY,
MAINTAIN ITS CURRENT INTENSITY THROUGH TAU 12, PRIMARILY DRIVEN BY
WARM SST AND GOOD POLEWARD OUTFLOW. AFTER TAU 12, DRY AIR, HIGH SHEAR,
AND QUICKLY LOWERING OCEAN HEAT CONTENT WILL CAUSE 21W TO WEAKEN
THROUGH THE REMAINDER OF THE FORECAST PERIOD.
MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT
THROUGH TAU 24, BUT QUICKLY SPREADS THEREAFTER AS PROXIMITY TO 20W
DECREASES AND THE STORMS INFLUENCE ONE ANOTHER. MODEL GUIDANCE IS
VERY POOR AFTER TAU 36. THE DEGREE OF UNCERTAINTY IN BINARY
INTERACTION IS MORE SIGNIFICANT FOR 21W SINCE IT IS FORECAST TO BE
THE WEAKER STORM AND THEREFORE MORE SUSCEPTIBLE TO INFLUENCE BY
20W. AS A RESULT, THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE
MULTI-MODEL CONSENSUS WITH LOW CONFIDENCE. RELIABLE INTENSITY AIDS
ARE IN GOOD AGREEMENT IN A GRADUAL WEAKENING THROUGH TAU 72. AN
EMERGING POSSIBILITY WIT…
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: WNW (300°), 5.8 kt | Gust: 7.8 kt
Pressure: 29.98 | Air Temp: 86.2 °F
Water Temp: 86.9 °F | Dew Point: 77.9 °F
Swell: 1.0 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.
