Alert archive / Tennessee / Mesoscale Discussions in 2003

Mesoscale Discussion 25

January 16, 20039 counties in Kentucky; 15 counties in Tennessee; 7 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jan 16, 2003, 12:07 PM EST for 9 counties in Kentucky; 15 counties in Tennessee; 7 counties in Virginia. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jan 16, 2003, 12:07 PM EST (17:07 UTC)
Expired
Jan 16, 2003, 4:00 PM EST
In force
4 hr
Issued by
the Storm Prediction Center
All 31 counties

Bell County, KY, Clinton County, KY, Harlan County, KY, Knox County, KY, Leslie County, KY, Letcher County, KY, McCreary County, KY, Wayne County, KY, Whitley County, KY, Campbell County, TN, Claiborne County, TN, Clay County, TN, Fentress County, TN, Grainger County, TN, Hancock County, TN, Hawkins County, TN, Jackson County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Scott County, TN, Sullivan County, TN, Union County, TN, City of Bristol, VA, City of Norton, VA, Dickenson County, VA, Lee County, VA, Russell County, VA, Scott County, VA, Wise County, VA

The radar

The Knoxville radar (KMRX), 77 km from the middle of the area, began a volume at 17:07 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

Nashville Metro, TN (KBNA), launched 12:00Z, 5.1 hours before the alert went out and 231 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, Nashville Metro, TN at 12:00Z on 2003-01-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Nashville Metro, TN at 12:00Z on 2003-01-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 250 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2377 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
250 m²/s²
0-3 km storm-relative helicity
355 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.

951 
ACUS11 KWNS 161707
SWOMCD
SPC MCD 161707 
TNZ000-KYZ000-VAZ000-162100-

MESOSCALE DISCUSSION 0025
NWS STORM PREDICTION CENTER NORMAN OK
1107 AM CST THU JAN 16 2003

AREAS AFFECTED...PARTS OF NRN/ERN TN...SERN KY...SWRN VA

CONCERNING...HEAVY SNOW

VALID 161707Z - 162100Z

BAND OF HEAVY SNOW WITH ACCUMULATION RATES AROUND 1 INCH PER HOUR
APPEARS LIKELY TO DEVELOP DURING THE NEXT FEW HOURS.


90 TO 100 KT CYCLONIC MID-LEVEL JET STREAK CONTINUES TO NOSE INTO
THE TENNESSEE VALLEY.  AGEOSTROPHIC FORCING IN EXIT REGION OF
THIS SPEED MAXIMUM HAS SUPPORTED AREA OF ENHANCED UPWARD VERTICAL
MOTION AND ASSOCIATED MODERATE TO HEAVY SNOW IN THE VICINITY OF
NASHVILLE TN.  THIS APPEARS LIKELY TO SPREAD/DEVELOP EAST
NORTHEASTWARD DURING THE NEXT 3 TO 4 HOURS...WITH BAND OF HEAVY
SNOW EVOLVING ALONG TIGHTENING LOW/MID-LEVEL BAROCLINIC ZONE EAST
OF NASHVILLE INTO AREAS NEAR/SOUTH OF LONDON KY AND NEAR/NORTH OF
BRISTOL TN.


ALTHOUGH LOW-LEVELS ARE QUITE DRY ACROSS THIS REGION...INTENSITY
OF PRECIPITATION...WITH STRONG LIFT IN FAVORABLE MID-LEVEL
DENDRITIC GROWTH LAYER...SHOULD QUICKLY SATURATE AIR MASS.  THIS
WILL SUPPORT ACCUMULATING SNOWS...WHICH SHOULD PERSIST FOR AT
LEAST A 3 TO 4 HOUR PERIOD THIS AFTERNOON.

..KERR.. 01/16/2003

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

36368597 36598577 36878495 37068386 37228301 37248241
36908186 36428226 36338310 36178381 36088462 36068550

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 16, 3:50 PM ESTMesoscale DiscussionSPCAlleghany, Amherst, Bath, Bedford, Bland, Botetourt and 28 more6 hr

Nearby

Mesoscale Discussions in Tennessee, 2003Mesoscale Discussions in Kentucky, 2003Mesoscale Discussions in Virginia, 2003Every mesoscale discussion in 2003

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.