Alert archive / North Carolina / Tornado Watches in 2021
Tornado Watch 42
The Storm Prediction Center issued this tornado watch at Mar 18, 2021, 4:45 PM EDT for 26 counties in North Carolina. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 18, 2021, 4:45 PM EDT (20:45 UTC)
- Expired
- Mar 18, 2021, 8:53 PM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 55 kt
All 26 counties
Alamance County, NC, Anson County, NC, Chatham County, NC, Cumberland County, NC, Davidson County, NC, Durham County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Richmond County, NC, Scotland County, NC, Stanly County, NC, Vance County, NC, Wake County, NC, Warren County, NC
The radar
The Raleigh/Durham radar (KRAX), 25 km from the middle of the area, began a volume at 20:46 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 50%
Warnings issued inside it
17 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 18, 4:54 PM EDT | Tornado Warning | RAH | Guilford, Randolph | 66 min |
| Mar 18, 5:07 PM EDT | Severe Thunderstorm Warning | RAH | Halifax | 23 min |
| Mar 18, 5:13 PM EDT | Severe Thunderstorm Warning | RAH | Alamance, Chatham, Davidson, Guilford, Randolph | 62 min |
| Mar 18, 5:34 PM EDT | Tornado Warning | RAH | Alamance, Guilford | 26 min |
| Mar 18, 5:37 PM EDT | Severe Thunderstorm Warning | RAH | Montgomery, Randolph, Stanly | 38 min |
| Mar 18, 5:58 PM EDT | Tornado Warning | RAH | Alamance, Durham, Orange, Person | 62 min |
| Mar 18, 6:07 PM EDT | Severe Thunderstorm Warning | RAH | Anson, Richmond | 38 min |
| Mar 18, 6:09 PM EDT | Severe Thunderstorm Warning | RAH | Alamance, Orange | 66 min |
| Mar 18, 6:13 PM EDT | Severe Thunderstorm Warning | RAH | Montgomery, Moore, Randolph, Stanly | 47 min |
| Mar 18, 6:39 PM EDT | Tornado Warning | RAH | Durham, Orange | 34 min |
| Mar 18, 6:41 PM EDT | Tornado Warning | RAH | Granville | 34 min |
| Mar 18, 6:45 PM EDT | Severe Thunderstorm Warning | RAH | Anson, Hoke, Montgomery, Moore, Richmond | 45 min |
| Mar 18, 6:57 PM EDT | Tornado Warning | RAH | Granville | 48 min |
| Mar 18, 6:59 PM EDT | Severe Thunderstorm Warning | RAH | Alamance, Chatham, Orange, Randolph | 21 min |
| Mar 18, 7:11 PM EDT | Tornado Warning | RAH | Halifax, Vance, Warren | 54 min |
| Mar 18, 7:25 PM EDT | Tornado Warning | RAH | Franklin, Vance, Warren | 47 min |
| Mar 18, 7:30 PM EDT | Severe Thunderstorm Warning | RAH | Cumberland, Harnett, Hoke, Lee, Moore | 45 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 8.8 hours before the alert went out and 111 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 486 m above ground
- 0-6 km bulk shear
- 67 kt
- 0-1 km storm-relative helicity
- 470 m²/s²
- 0-3 km storm-relative helicity
- 562 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
201 WWUS20 KWNS 182042 SEL2 SPC WW 182042 NCZ000-190100- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 42 NWS Storm Prediction Center Norman OK 445 PM EDT Thu Mar 18 2021 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central North Carolina * Effective this Thursday afternoon and evening from 445 PM until 900 PM EDT. * Primary threats include... A couple tornadoes possible Isolated damaging wind gusts to 65 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...A cluster of strong to locally severe thunderstorms should spread northeast across the central North Carolina Piedmont region through early evening. The tornado watch area is approximately along and 55 statute miles east and west of a line from 45 miles north northeast of Raleigh NC to 30 miles south southwest of Southern Pines NC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 40...WW 41... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 23040. ...Grams
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 18, 10:34 AM EDT | Mesoscale Discussion | SPC | Cabarrus, Cleveland, Gaston, Lincoln, Mecklenburg, Rowan and 1 more | 2 hr |
| Mar 18, 2:08 PM EDT | Tornado Watch | SPC | Cabarrus, Cleveland, Gaston, Lincoln, Mecklenburg, Union | 4 hr |
| Mar 18, 3:10 PM EDT | Mesoscale Discussion | SPC | Cabarrus, Cleveland, Gaston, Lincoln, Mecklenburg, Rutherford and 2 more | 3 hr |
| Mar 18, 5:09 PM EDT | Tornado Watch | SPC | Bertie, Camden, Chowan, Currituck, Gates, Hertford and 3 more | 6 hr |
| Mar 18, 5:57 PM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Beaufort, Bertie, Cabarrus, Camden and 45 more | 63 min |
| Mar 18, 7:49 PM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Chatham, Cumberland, Durham, Edgecombe and 21 more | 56 min |
Nearby
Tornado Watches in North Carolina, 2021Every tornado watch in 2021
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.