Alert archive / North Carolina / Flash Flood Warnings in 2020
Flash Flood Warning 49, NWS Greenville-Spartanburg, SC
NWS Greenville-Spartanburg, SC issued this flash flood warning at Aug 15, 2020, 4:50 PM EDT for Mecklenburg County, Union County, North Carolina. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 15, 2020, 4:50 PM EDT (20:50 UTC)
- Expired
- Aug 15, 2020, 7:45 PM EDT
- In force
- 3 hr
- Issued by
- NWS Greenville-Spartanburg, SC
- Area
- Storm-based polygon
- Flood severity
- None
Counties Mecklenburg County, NC, Union County, NC
The radar
The Columbia radar (KCAE), 137 km from the middle of the area, began a volume at 20:54 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 8.8 hours before the alert went out and 125 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 585 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 521 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 45 m²/s²
- 0-3 km storm-relative helicity
- 61 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
The text
As transmitted.
182
WGUS52 KGSP 152050
FFWGSP
NCC119-179-152345-
/O.NEW.KGSP.FF.W.0049.200815T2050Z-200815T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Greenville-Spartanburg SC
450 PM EDT Sat Aug 15 2020
The National Weather Service in Greenville-Spartanburg has issued a
* Flash Flood Warning for...
Southeastern Mecklenburg County in the piedmont of North Carolina...
Union NC County in the piedmont of North Carolina...
* Until 745 PM EDT.
* At 450 PM EDT, Doppler radar and automated rain gauges indicated
repeated thunderstorms crossing Union County and southeast
Mecklenburg County North Carolina, producing heavy rainfall at
rates of 1 to 2 inches per hour across the warned area. Between 1
and 2 inches of rain have already fallen in the past 3 hours, and
some road closures due to flooding have already occurred.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Doppler radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flash flooding include...
Monroe, South Charlotte, Matthews, Mint Hill, Indian Trail,
Weddington, Stallings, Unionville, Wesley Chapel, Wingate, Waxhaw,
Marshville, Lake Park, Mineral Springs, Hemby Bridge, Marvin,
Fairview In Union County and New Salem.
Flash flooding will develop quickly along Crooked Creek and Price
Mill Creek in the Indian Trail Community.
Additional rainfall amounts of 1 to 3 inches are possible in the
warned area over the next two hours.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3504 8088 3523 8058 3516 8044 3517 8042
3516 8041 3518 8037 3517 8036 3520 8028
3493 8031 3491 8038 3487 8079 3494 8078
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR
$$
HGWhat forecasters said that day
The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before this flash flood warning went out at Aug 15, 2:52 PM EDT, 1 hour 58 minutes earlier.
Area forecast discussion, Aug 15, 2:52 PM EDT, 1 hour 58 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
252 PM EDT Sat Aug 15 2020
.SYNOPSIS...
Showers and thunderstorms will diminish overnight tonight.
Thunderstorm chances will return to more typical levels for Sunday
and Monday, then increase through the week as an upper level trough
becomes well established. Highs will be around normal through the
first part of the week then fall below normal.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 245 PM EDT Saturday: A Flash Flood Watch remains in effect for
portions of North Carolina through tonight.
With upper troughing moving overhead the western fringes of the
Southeast and developing sfc feature near the area, showers and
thunderstorms continue to blossom in coverage as they move from SW
to ENE across the FA ahead of an approaching front as seen from
latest radar imagery, with a noticeable uptick in lightning over the
past hour. Rainfall rates through much of the morning hours were
fairly light in nature, but latest precip rates indicate an
increasing trend with even local rivers/streams slowly beginning to
respond. While gusty winds cannot be entirely ruled out in stronger
storms, the primary threat will be heavy downpours and flooding
through this evening with plenty of available forcing and moisture
in place (PWATs around 2 inches) and already saturated soils given
recent rainfall. Isolated flash flooding will be possible, but
confidence is low given decent storm motion. Current temperatures
range from the low to mid 70s to lower 80s attm, with variations
expected given rain-cooled air in many locations.
Expect activity to wane tonight with lingering light showers
possible overnight as the sfc low and trailing cold front slowly
push through the area and upper troughing moves overhead. While
patchy fog will be possible given light winds and saturated soils,
expect low stratus to be the main concern overnight per latest fcst
soundings. Guidance continues to suggest low clouds lingering
through mid Sunday morning at the latest as drier air gradually
makes it's way into the area with NW flow. Min temps will drop to
around normal.
Despite the slow infiltration of drier air in the wake of the
exiting system, lingering available moisture and instability will
warrant the potential for isolated convection once again Sunday.
Otherwise, expect a mixture of sunshine and clouds with max
temperatures falling a few degrees short of normal.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 2pm EDT Saturday: Weather Monday and Tuesday is largely the
result of a longwave trough over the eastern CONUS, with a southern
extent over the GSP CWA. This far south, dynamical factors are
somewhat weak, but a frontal boundary is expected to pass through
the area from northwest to southeast on Monday, with an enhanced
chance for precipitation as it passes, and a reduction behind it as
moisture is reduced. Showers on Monday may be more confined to
piedmont areas where the front may better interact with moisture,
while on Tuesday, what showers that manage to form will be more
likely over the mountains where elevated surface heating has a
better chance of breaking the cap. MLCAPE will be weak on Monday
behind the previous front, and confined to piedmont areas, by
Tuesday afternoon behind the next front, it will be even weaker at
below 400 j/kg. Longwave pattern is expected to help temperatures
to remain just below climo, and notably below recent weeks. With
still weak dynamics at play, surface features are poorly defined,
and winds are expected to remain light, outside of outflows from
storms.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
As of 2pm EDT Saturday: Longwave eastern trough gives way
Wednesday/Thursday as northern extent pulls out, being replaced by
some ridging east of the continent and, relevant to GSP, a shortwave
trough over the Southern Mississippi basin. This trough will help
to maintain and increase moisture back up to sub-tropical levels,
and keep a chance for afternoon thunderstorms in the forecast for
Wednesday onward. GFS surface forecast gains 4 degrees in dewpoint
on Wednesday, regaining the moisture lost on Tuesday. The GFS model
brings the southwest shortwave across the area earlier than the EC,
with Saturday afternoon being a respite from afternoon
thunderstorms, if it is correct. Seasonally weak synoptic features
will lead to near normal temperatures and light winds through the
extended forecast.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
At KCLT and Elsewhere: Expect scattered to widespread showers and
thunderstorms to continue across the area through the rest of today
and into this evening, which will bring periods of flight
restrictions to TAF sites due to heavy downpours/patchy fog and
lowered cigs, as noted by TEMPO groups. Expect a majority of the
activity to wane into tonight, with a few lingering showers possible
overnight. While patchy fog will be possible especially given
saturated soils, latest fcst soundings continue to suggest low cigs
to be the primary concern for some TAF sites with MVFR/IFR/possible
LIFR overnight. Cigs may be gradual to lift Sunday morning, thus
have kept with VFR/MVFR trend. Winds will remain light overall, with
brief gusty winds possible in any stronger storms.
Outlook: Isolated to widely scattered tstms expected Sunday and
Monday. An uptick in thunderstorm coverage is then likely Tuesday
through Wednesday. Fog and low stratus restrictions will be possible
each morning, especially over the usual mountain valleys. Otherwise
expect VFR.
Confidence Table...
19-01Z 01-07Z 07-13Z 13-18Z
KCLT High 99% Med 79% Med 74% Med 79%
KGSP High 94% High 97% Med 76% Med 78%
KAVL High 91% High 81% Low 46% High 80%
KHKY Med 69% Low 53% Med 69% Med 74%
KGMU High 95% High 99% Med 70% Med 75%
KAND High 95% High 100% Med 67% Med 72%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Flash Flood Watch until midnight EDT tonight for NCZ033-
035>037-056-057-501>506.
SC...None.
&&
SYNOPSIS...DEO
NEAR TERM...12
SHORT TERM...WJM
LONG TERM...WJM
AVIATION...12Hazardous weather outlook, Aug 15, 3:36 PM EDT, 1 hour 14 minutes before
Hazardous Weather Outlook National Weather Service Greenville-Spartanburg SC 336 PM EDT Sat Aug 15 2020 GAZ010-017-018-026-028-029-NCZ048>053-058-059-062>065-068>072-082- 507>510-SCZ001>014-019-161945- Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Madison-Yancey- Mitchell-Swain-Haywood-Buncombe-Graham-Northern Jackson-Macon- Southern Jackson-Transylvania-Henderson-Cleveland-Lincoln-Gaston- Mecklenburg-Cabarrus-Union NC-Rutherford Mountains- Greater Rutherford-Polk Mountains-Eastern Polk-Oconee Mountains- Pickens Mountains-Greenville Mountains-Greater Oconee- Greater Pickens-Greater Greenville-Spartanburg-Cherokee-York- Anderson-Abbeville-Laurens-Union SC-Chester-Greenwood- 336 PM EDT Sat Aug 15 2020 This Hazardous Weather Outlook is for northeast Georgia, piedmont North Carolina, western North Carolina and upstate South Carolina. .DAY ONE...This afternoon and tonight. Widespread showers and thunderstorms will continue to develop across the region through the evening hours. The primary threats with these storms will be cloud-to-ground lightning and locally heavy rainfall. The storms and heavy rain showers will occasionally become stationary, posing a threat of excessive rainfall and flash flooding, especially in locations that have received heavy rainfall over the past few days. .DAYS TWO THROUGH SEVEN...Sunday through Friday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... None. NCZ033-035>037-056-057-501>506-161945- Avery-Alexander-Iredell-Davie-Catawba-Rowan-Caldwell Mountains- Greater Caldwell-Burke Mountains-Greater Burke-McDowell Mountains- Eastern McDowell- 336 PM EDT Sat Aug 15 2020 ...FLASH FLOOD WATCH IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... This Hazardous Weather Outlook is for piedmont North Carolina and western North Carolina. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flash Flood Watch. Widespread thunderstorms can produce cloud-to- ground lightning and occasional gusty winds. .DAYS TWO THROUGH SEVEN...Sunday through Friday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines.
In the hours before
Special weather statement, Aug 15, 4:01 PM EDT, 49 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
401 PM EDT Sat Aug 15 2020
GAZ029-SCZ010-011-152030-
Elbert GA-Anderson SC-Abbeville SC-
401 PM EDT Sat Aug 15 2020
...STRONG THUNDERSTORMS WILL IMPACT EASTERN ELBERT...SOUTHEASTERN
ANDERSON AND WESTERN ABBEVILLE COUNTIES UNTIL 430 PM EDT...
At 400 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 6 miles southeast of Anderson to 8 miles south of
Elberton, and moving east at 15 mph.
Locations to be impacted include...
Elberton, Calhoun Falls, Iva, Lake Secession, Starr, Lowndesville,
Lake Strom Thurmond, Russell State Park, Nancy Hart State Park and
Middleton.
Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.
Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.
&&
LAT...LON 3399 8283 3398 8284 3398 8286 3400 8288
3401 8290 3449 8266 3449 8242 3398 8260
3398 8263 3397 8264 3399 8266 3398 8270
3398 8273 3397 8278
TIME...MOT...LOC 2000Z 276DEG 13KT 3443 8259 3398 8284
KRENTZSpecial weather statement, Aug 15, 4:04 PM EDT, 46 minutes before
Special Weather Statement National Weather Service Greenville-Spartanburg SC 404 PM EDT Sat Aug 15 2020 NCZ508-510-SCZ007-008-152030- Greater Rutherford NC-Eastern Polk NC-Cherokee SC-Spartanburg SC- 404 PM EDT Sat Aug 15 2020 ...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN RUTHERFORD... EASTERN POLK...NORTH CENTRAL SPARTANBURG AND NORTHWESTERN CHEROKEE COUNTIES UNTIL 430 PM EDT... At 404 PM EDT, Doppler radar was tracking a strong thunderstorm 4 miles southwest of Rutherfordton, moving east at 15 mph. Locations to be impacted include... Forest City, Rutherfordton, Columbus, Spindale, Tryon, Ellenboro, Bostic, Chesnee, Cliffside and Mill Spring. Wind gusts up to 40 mph and pea size hail will be possible in these areas. PRECAUTIONARY/PREPAREDNESS ACTIONS... The combination of gusty winds and saturated soil conditions will cause scattered trees and power lines to fall. Seek shelter inside an interior room. Torrential rainfall may flood areas with poor drainage, such as ditches and underpasses. Avoid these areas and do not cross flooded roads. Water levels of small streams may also rise rapidly. Seek higher ground if threatened by flood waters. && LAT...LON 3546 8174 3514 8177 3521 8226 3540 8208 TIME...MOT...LOC 2004Z 276DEG 13KT 3530 8201 KRENTZ
Special weather statement, Aug 15, 4:21 PM EDT, 29 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
421 PM EDT Sat Aug 15 2020
SCZ005>008-152100-
Greater Pickens SC-Cherokee SC-Spartanburg SC-Greater Greenville SC-
421 PM EDT Sat Aug 15 2020
...STRONG THUNDERSTORMS WILL IMPACT EAST CENTRAL GREENVILLE...
NORTHERN SPARTANBURG...NORTHERN CHEROKEE AND EAST CENTRAL PICKENS
COUNTIES UNTIL 500 PM EDT...
At 421 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 12 miles north of Spartanburg to 3 miles
northeast of Easley, and moving east at 30 mph.
Locations to be impacted include...
Greenville Downtown, Spartanburg, Gaffney, Greenville Eastside, West
Greenville, Greer, Mauldin, Taylors, Berea and Five Forks.
Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.
Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.
&&
LAT...LON 3489 8266 3502 8236 3506 8222 3509 8222
3518 8201 3515 8139 3477 8226
TIME...MOT...LOC 2021Z 273DEG 26KT 3513 8189 3485 8254
KRENTZSpecial weather statement, Aug 15, 4:23 PM EDT, 27 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
423 PM EDT Sat Aug 15 2020
GAZ029-SCZ006-010>012-019-152100-
Elbert GA-Laurens SC-Anderson SC-Abbeville SC-Greenwood SC-
Greater Greenville SC-
423 PM EDT Sat Aug 15 2020
...STRONG THUNDERSTORMS WILL IMPACT SOUTHEASTERN ELBERT...WESTERN
LAURENS...SOUTHEASTERN GREENVILLE...SOUTHEASTERN ANDERSON...ABBEVILLE
AND WESTERN GREENWOOD COUNTIES UNTIL 500 PM EDT...
At 423 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 13 miles east of Anderson to 13 miles north of
Washington, and moving east at 30 mph.
Locations to be impacted include...
Abbeville, Belton, Honea Path, Ware Shoals, Calhoun Falls, Due West,
Gray Court, Donalds, Cokesbury and Hodges.
Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.
Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.
&&
LAT...LON 3398 8261 3397 8264 3399 8265 3398 8267
3457 8251 3469 8205 3401 8225 3397 8231
3406 8233 3406 8244 3408 8248 3407 8250
3407 8253 3401 8260 3399 8258 3396 8257
TIME...MOT...LOC 2023Z 253DEG 26KT 3459 8243 3391 8265
KRENTZLocal storm report, Aug 15, 4:33 PM EDT, 17 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
433 PM EDT SAT AUG 15 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0300 PM DEBRIS FLOW 4 NE BAT CAVE 35.50N 82.24W
08/15/2020 BUNCOMBE NC 911 CALL CENTER
911 CALL CENTER AND SOCIAL MEDIA REPORTED LANDSLIDE ON
ROCK CREEK RD. OVER HALF OF THE ROADWAY WASHED AWAY.
&&Special weather statement, Aug 15, 4:33 PM EDT, 17 minutes before
Special Weather Statement National Weather Service Greenville-Spartanburg SC 433 PM EDT Sat Aug 15 2020 NCZ068-508-152100- Greater Rutherford NC-Cleveland NC- 433 PM EDT Sat Aug 15 2020 ...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN RUTHERFORD AND SOUTHWESTERN CLEVELAND COUNTIES UNTIL 500 PM EDT... At 433 PM EDT, Doppler radar was tracking a strong thunderstorm 8 miles east of Forest City, or near Ellenboro, moving east at 15 mph. Locations to be impacted include... Shelby, Forest City, Boiling Springs NC, Lawndale, Patterson Springs, Fallston, Polkville, Ellenboro, Lattimore and Mooresboro. Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates up to 2 inches per hour will be possible in these areas. PRECAUTIONARY/PREPAREDNESS ACTIONS... The combination of gusty winds and saturated soil conditions will cause scattered trees and power lines to fall. Seek shelter inside an interior room. Torrential rainfall may flood areas with poor drainage, such as ditches and underpasses. Avoid these areas and do not cross flooded roads. Water levels of small streams may also rise rapidly. Seek higher ground if threatened by flood waters. && LAT...LON 3526 8189 3544 8180 3547 8150 3522 8151 TIME...MOT...LOC 2033Z 271DEG 15KT 3536 8171 KRENTZ
The office that day
Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 14, 10:47 PM EDT | Special Weather Statement | GSP | Alexander | 73 min |
| Aug 15, 12:19 AM EDT | Flash Flood Warning | GSP | Catawba | 6 hr |
| Aug 15, 12:56 AM EDT | Flash Flood Warning | GSP | Burke, Caldwell | 6 hr |
| Aug 15, 2:19 AM EDT | Flash Flood Warning | GSP | Alexander, Burke, Caldwell, Catawba | 4 hr |
| Aug 15, 4:29 AM EDT | Areal Flood Advisory | GSP | Alexander, Catawba | 5 hr |
| Aug 15, 10:48 AM EDT | River Flood Advisory | GSP | Henderson, Transylvania | 8 hr |
| Aug 15, 3:09 PM EDT | Special Weather Statement | GSP | Union | 36 min |
| Aug 15, 4:04 PM EDT | Special Weather Statement | GSP | Polk, Rutherford | 26 min |
| Aug 15, 4:28 PM EDT | Flash Flood Warning | GSP | Alexander, Burke, Caldwell, Catawba, Iredell | 2 hr |
| Aug 15, 4:33 PM EDT | Special Weather Statement | GSP | Cleveland | 27 min |
| Aug 15, 5:57 PM EDT | Special Weather Statement | GSP | Iredell | 33 min |
| Aug 15, 6:10 PM EDT | Flash Flood Warning | GSP | Catawba, Davie, Iredell, Rowan | 2 hr |
| Aug 15, 7:43 PM EDT | Special Weather Statement | GSP | Cabarrus, Mecklenburg | 32 min |
Nearby
Flash Flood Warnings in North Carolina, 2020Every flash flood warning in 2020
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.