Alert archive / North Carolina / Mesoscale Discussions in 2025

Mesoscale Discussion 921

May 21, 202512 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at May 21, 2025, 12:48 PM EDT for 12 counties in North Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 21, 2025, 12:48 PM EDT (16:48 UTC)
Expired
May 21, 2025, 3:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%

Counties Beaufort County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Currituck County, NC, Dare County, NC, Hyde County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC, Washington County, NC

The radar

The Morehead City radar (KMHX), 104 km from the middle of the area, began a volume at 16:49 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.

The nearest sounding before it

Newport, NC (KMHX), launched 12:00Z, 4.8 hours before the alert went out and 104 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.

Skew-T log-pSkew-T log-p diagram, Newport, NC at 12:00Z on 2025-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1289 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Newport, NC at 12:00Z on 2025-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1289 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
890 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.6
Supercell composite
8.2

Open this sounding in Storm Lab

The text

As transmitted.

512 
ACUS11 KWNS 211649
SWOMCD
SPC MCD 211648 
NCZ000-211915-

Mesoscale Discussion 0921
NWS Storm Prediction Center Norman OK
1148 AM CDT Wed May 21 2025

Areas affected...far eastern North Carolina

Concerning...Severe potential...Watch unlikely 

Valid 211648Z - 211915Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated strong storms may develop this afternoon over far
eastern North Carolina. Localized hail or wind may occur.

DISCUSSION...Surface analysis shows a low over northeast
NC/southeast VA, with a cold front extending westward across
northern NC. South of this front, westerly winds and strong heating
are steepening boundary layer lapse rates, and removing convective
inhibition. Meanwhile, a narrow zone of mid 70s F dewpoints remains
in place over far eastern NC. Continued heating will yield over 2000
J/kg MLCAPE, beneath moderate westerlies aloft with around 50 kt
deep layer shear.

Although the westerly flow regime will eventually result in a drying
air mass, a window may exist in the near term for a few strong to
severe storms. Isolated marginal hail or a strong downburst cannot
be ruled out.

..Jewell/Guyer.. 05/21/2025

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...AKQ...MHX...

LAT...LON   36217671 36417640 36457580 36337571 36037553 35587539
            35237548 35037602 34697635 34577651 34627665 34937691
            35447704 35837695 36217671 

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 9:14 PM EDTMesoscale DiscussionSPCCherokee, Clay, Graham2 hr

Nearby

Mesoscale Discussions in North Carolina, 2025Every mesoscale discussion in 2025

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.