Alert archive / Ohio / Mesoscale Discussions in 2012

Mesoscale Discussion 655

May 1, 20124 states

The Storm Prediction Center issued this mesoscale discussion at May 1, 2012, 9:33 PM EDT for 4 states. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued: May 1, 2012, 9:33 PM EDT (01:33 UTC)
Expired: May 1, 2012, 10:30 PM EDT
In force: 57 min
Issued by: the Storm Prediction Center

All 108 counties

Bartholomew County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Clinton County, IN, Dearborn County, IN, Decatur County, IN, Delaware County, IN, Fayette County, IN, Franklin County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Jackson County, IN, Jennings County, IN, Johnson County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Monroe County, IN, Morgan County, IN, Ohio County, IN, Randolph County, IN, Ripley County, IN, Rush County, IN, Shelby County, IN, Switzerland County, IN, Tipton County, IN, Union County, IN, Wayne County, IN, Boone County, KY, Boyd County, KY, Bracken County, KY, Campbell County, KY, Carroll County, KY, Carter County, KY, Gallatin County, KY, Grant County, KY, Greenup County, KY, Kenton County, KY, Lewis County, KY, Mason County, KY, Owen County, KY, Pendleton County, KY, Robertson County, KY, Adams County, OH, Athens County, OH, Belmont County, OH, Brown County, OH, Butler County, OH, Clark County, OH, Clermont County, OH, Clinton County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Gallia County, OH, Greene County, OH, Guernsey County, OH, Hamilton County, OH, Highland County, OH, Hocking County, OH, Jackson County, OH, Lawrence County, OH, Licking County, OH, Madison County, OH, Meigs County, OH, Monroe County, OH, Montgomery County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pickaway County, OH, Pike County, OH, Preble County, OH, Ross County, OH, Scioto County, OH, Vinton County, OH, Warren County, OH, Washington County, OH, Barbour County, WV, Braxton County, WV, Cabell County, WV, Calhoun County, WV, Clay County, WV, Doddridge County, WV, Gilmer County, WV, Harrison County, WV, Jackson County, WV, Kanawha County, WV, Lewis County, WV, Marshall County, WV, Mason County, WV, Nicholas County, WV, Ohio County, WV, Pleasants County, WV, Putnam County, WV, Ritchie County, WV, Roane County, WV, Tyler County, WV, Upshur County, WV, Webster County, WV, Wetzel County, WV, Wirt County, WV, Wood County, WV

The radar

The Cincinnati radar (KILN), 29 km from the middle of the area, began a volume at 01:34 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

Pittsburgh, PA (KPIT), launched 00:00Z, 1.6 hours before the alert went out and 344 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1907 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 53 m²/s²
0-3 km storm-relative helicity: 144 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

421 
ACUS11 KWNS 020134
SWOMCD
SPC MCD 020133
WVZ000-PAZ000-OHZ000-KYZ000-INZ000-020230-

MESOSCALE DISCUSSION 0655
NWS STORM PREDICTION CENTER NORMAN OK
0833 PM CDT TUE MAY 01 2012

AREAS AFFECTED...CNTRL/ERN IND...SRN OH...FAR NRN KY...WRN/CNTRL WV

CONCERNING...TORNADO WATCH 218...222...

VALID 020133Z - 020230Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 218...222...CONTINUES.

SUMMARY...STORMS LOCATED FROM CNTRL IND INTO SRN OH ARE BECOMING
INCREASINGLY ELEVATED AND POSE A MARGINAL TORNADO THREAT. STORMS
ENTERING WRN WV WILL ENCOUNTER AN AIRMASS SLIGHTLY MORE FAVORABLE
FOR SURFACE BASED THUNDERSTORMS. ACTIVITY MAY SPREAD EWD INTO CNTRL
WV...WHICH COULD REQUIRE SPATIAL EXPANSION OF WW 222 BY LOCAL WFO.

DISCUSSION...AT 0130Z...WARM FRONT EXTENDED SEWD FROM W-CNTRL IND
INTO FAR NRN KY...AND THEN CURVED BACK TO THE NE INTO FAR WRN WV.
SURFACE AIRMASS N OF THE WARM FRONT HAS BEEN WORKED OVER EXTENSIVELY
BY MULTIPLE ROUNDS OF THUNDERSTORMS...YIELDING TEMPERATURES THAT ARE
NOW IN THE 60S. OBJECTIVE ANALYSIS GUIDANCE INDICATES MUCAPE VALUES
RANGE FROM 500-1000 J/KG N OF THE FRONT...AND MAY SUPPORT A THREAT
FOR LARGE HAIL AND AN ISOLATED DAMAGING WIND GUST/BRIEF
TORNADO...GIVEN EFFECTIVE BULK WIND DIFFERENCE VALUES FROM 40-50 KT.
FARTHER E OVER WV...SURFACE TEMPERATURES REMAIN NEAR 70 WITH
DEWPOINTS IN THE LOW 60S. THIS IS ALLOWING A CORRIDOR OF HIGHER
THETA-E AND SURFACE BASED INSTABILITY TO PERSIST. IN ADDITION...RLX
VWP SHOWS SHEAR PROFILES QUITE FAVORABLE FOR SUPERCELLS...WITH 0-1
KM SRH NEAR 200 M2 S-2 AND 0-6 KM BULK WIND DIFFERENCE IN EXCESS OF
40 KT. GIVEN THIS ENVIRONMENT...SVR THREAT COULD SPREAD EWD FROM WRN
INTO CNTRL WV DURING THE NEXT HR OR TWO.

..GARNER.. 05/02/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK...IWX...IND...

LAT...LON   40738672 40318480 39928480 39918412 40278272 40248218
            40208044 39488049 39127992 38538010 38088073 38278200
            38188293 38508362 38438400 38578421 38548444 38348477
            38668520 38918521 38928552 38748588 38688632 38688668
            40738672

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 2, 3:46 PM EDT	Mesoscale Discussion	SPC	Bartholomew, Boone, Brown, Clay, Decatur, Delaware and 24 more	119 min
May 2, 4:56 PM EDT	Mesoscale Discussion	SPC	Ashtabula, Carroll, Columbiana, Cuyahoga, Geauga, Lake and 8 more	2 hr

Nearby

Mesoscale Discussions in Ohio, 2012 Mesoscale Discussions in Indiana, 2012 Mesoscale Discussions in West Virginia, 2012 Every mesoscale discussion in 2012

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.