Alert archive / Virginia / Mesoscale Discussions in 2007
Mesoscale Discussion 608
The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2007, 7:33 PM EDT for 8 counties in Virginia. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- Apr 27, 2007, 7:33 PM EDT (23:33 UTC)
- Expired
- Apr 27, 2007, 9:00 PM EDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
Counties Accomack County, VA, City of Poquoson, VA, Gloucester County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, Northampton County, VA, York County, VA
The radar
The Norfolk radar (KAKQ), 100 km from the middle of the area, began a volume at 23:37 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
Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.6 hours before the alert went out and 78 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
- 130 J/kg
- Mixed-layer CIN
- -35 J/kg
- Mixed-layer LCL
- 479 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 223 m²/s²
- 0-3 km storm-relative helicity
- 224 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 272333 SWOMCD SPC MCD 272333 VAZ000-280100- MESOSCALE DISCUSSION 0608 NWS STORM PREDICTION CENTER NORMAN OK 0633 PM CDT FRI APR 27 2007 AREAS AFFECTED...FAR ERN VA CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 272333Z - 280100Z A SEVERE THREAT SHOULD CONTINUE ACROSS FAR ERN VA FOR 1 TO 2 HOURS. HAIL AND STRONG GUSTY WINDS WILL LIKELY BE THE PRIMARY THREATS. HOWEVER...THE SEVERE POTENTIAL SHOULD REMAIN TOO ISOLATED TO WARRANT A WW ACROSS THE REGION EARLY THIS EVENING. LATEST SFC ANALYSIS SHOWS A LOW ACROSS ERN VA WITH A COLD FRONT EXTENDING SWWD ACROSS CNTRL VA INTO CNTRL NC. A COUPLE OF SEVERE STORMS ARE LOCATED VERY NEAR THE SFC LOW IN AN AREA OF LOCALLY ENHANCED INSTABILITY WHERE MLCAPE VALUES RANGE FROM 1000 TO 1200 J/KG. THE WAKEFIELD VA WSR-88D VWP SHOWS STRONG VERTICAL SHEAR WHICH WILL BE SUFFICIENT TO CONTINUE A SUPERCELL THREAT ACROSS THE REGION FOR A FEW MORE HOURS. ALTHOUGH MID-LEVEL LAPSE RATES ARE NOT THAT STEEP...TEMPS ALOFT SHOWN ON OBJECTIVE ANALYSIS STILL APPEAR COLD ENOUGH FOR A HAIL THREAT. THE POTENTIAL FOR STRONG GUSTY WINDS WILL ALSO EXIST DUE TO STEEP LOW-LEVEL LAPSE RATES MAINLY SOUTH OF I-64. SFC TEMPS ARE MUCH COOLER OVER THE CHESAPEAKE BAY AND THIS SHOULD REDUCE THE SEVERE POTENTIAL AS STORMS MOVE GRADUALLY EWD EARLY THIS EVENING. ..BROYLES.. 04/27/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ... 37117601 37107651 37457666 37807639 37927602 37757558 37557551 37167559
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 11:29 AM EDT | Mesoscale Discussion | SPC | Charles City, Gloucester, Greensville, Isle of Wight, James City, Lancaster and 20 more | 61 min |
| Apr 27, 12:01 PM EDT | Severe Thunderstorm Watch | SPC | Accomack, Brunswick, Charles City, Dinwiddie, Gloucester, Greensville and 28 more | 5 hr |
| Apr 27, 3:33 PM EDT | Mesoscale Discussion | SPC | Accomack, Brunswick, Charles City, Chesterfield, Dinwiddie, Essex and 36 more | 117 min |
Nearby
Mesoscale Discussions in Virginia, 2007Every mesoscale discussion in 2007
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.