Alert archive / Virginia / Mesoscale Discussions in 2011
Mesoscale Discussion 221
The Storm Prediction Center issued this mesoscale discussion at Mar 10, 2011, 4:26 PM EST for Northampton County, North Carolina; 24 counties in Virginia. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Mar 10, 2011, 4:26 PM EST (21:26 UTC)
- Expired
- Mar 10, 2011, 6:00 PM EST
- In force
- 94 min
- Issued by
- the Storm Prediction Center
All 25 counties
Northampton County, NC, Amelia County, VA, Brunswick County, VA, Caroline County, VA, Chesterfield County, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Fredericksburg, VA, City of Hopewell, VA, City of Petersburg, VA, City of Richmond, VA, Cumberland County, VA, Dinwiddie County, VA, Fluvanna County, VA, Goochland County, VA, Greensville County, VA, Hanover County, VA, Henrico County, VA, Louisa County, VA, Nottoway County, VA, Orange County, VA, Powhatan County, VA, Prince George County, VA, Spotsylvania County, VA, Sussex County, VA
The radar
The Norfolk radar (KAKQ), 73 km from the middle of the area, began a volume at 21:28 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
Roanoke, VA (KRNK), launched 12:00Z, 9.4 hours before the alert went out and 153 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
- 8 J/kg
- Mixed-layer CIN
- -47 J/kg
- Mixed-layer LCL
- 486 m above ground
- 0-6 km bulk shear
- 77 kt
- 0-1 km storm-relative helicity
- 170 m²/s²
- 0-3 km storm-relative helicity
- 217 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
868
ACUS11 KWNS 102126
SWOMCD
SPC MCD 102126
NCZ000-VAZ000-102300-
MESOSCALE DISCUSSION 0221
NWS STORM PREDICTION CENTER NORMAN OK
0326 PM CST THU MAR 10 2011
AREAS AFFECTED...E-CNTRL NC THROUGH CNTRL VA
CONCERNING...SEVERE THUNDERSTORM WATCH 49...
VALID 102126Z - 102300Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 49
CONTINUES.
GREATEST POTENTIAL FOR ISOLATED DAMAGING WIND APPEARS TO BE ACROSS
N-CNTRL NC THROUGH CNTRL AND N-CNTRL VA NEXT COUPLE HOURS. IF
NECESSARY WW 49 CAN BE LOCALLY EXTENDED IN AREA INTO NERN NC AND ERN
VA AS LINE ADVANCES NEWD.
STRONGER PRESSURE FALLS AND SURFACE CYCLOGENESIS IS UNDERWAY ACROSS
N-CNTRL VA IN RESPONSE TO STRONG AGEOSTROPHIC FORCING/DPVA WITHIN
NEWD EJECTING NEGATIVE TILTED SHORTWAVE TROUGH. CONVECTION HAS
RECENTLY INTENSIFIED ACROSS CNTRL VA AS STRENGTHENING LOW LEVEL
CONVERGENCE OVERTAKES MOIST AXIS. VWP DATA INDICATE STRONG SLY
UNIDIRECTIONAL SHEAR PROFILES ALONG WITH 40-50 KT FLOW IN THE 0-1 KM
LAYER. EMBEDDED FAST MOVING BOWING SEGMENTS AND LEWP STRUCTURES
REMAIN POSSIBLE NEXT FEW HOURS MAINLY FROM NERN NC THROUGH CNTRL AND
N-CNTRL VA AS ACTIVITY DEVELOPS NNEWD.
..DIAL.. 03/10/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...LWX...RAH...RNK...
LAT...LON 36377796 37147831 38377832 38357750 37707717 36367716
36377796SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 10, 12:51 PM EST | Mesoscale Discussion | SPC | Alamance, Bladen, Caswell, Chatham, Columbus, Cumberland and 22 more | 114 min |
| Mar 10, 1:25 PM EST | Severe Thunderstorm Watch | SPC | Alamance, Bertie, Caswell, Chatham, Cumberland, Duplin and 31 more | 7 hr |
Nearby
Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in North Carolina, 2011Every mesoscale discussion in 2011
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.