Alert archive / Mississippi / Mesoscale Discussions in 2011
Mesoscale Discussion 84
The Storm Prediction Center issued this mesoscale discussion at Feb 3, 2011, 12:58 PM CST for 21 parishes in Louisiana; 33 counties in Mississippi. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 3, 2011, 12:58 PM CST (18:58 UTC)
- Expired
- Feb 3, 2011, 6:00 PM CST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 54 counties
Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Saint Helena Parish, LA, Saint Landry Parish, LA, Tensas Parish, LA, Vernon Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Attala County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Franklin County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS, Winston County, MS, Yazoo County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 137 km from the middle of the area, began a volume at 19:00 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
Jackson, MS (KJAN), launched 12:00Z, 7.0 hours before the alert went out and 132 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 883 m above ground
- 0-6 km bulk shear
- 77 kt
- 0-1 km storm-relative helicity
- 124 m²/s²
- 0-3 km storm-relative helicity
- 309 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
159
ACUS11 KWNS 031858
SWOMCD
SPC MCD 031858
ALZ000-MSZ000-LAZ000-040000-
MESOSCALE DISCUSSION 0084
NWS STORM PREDICTION CENTER NORMAN OK
1258 PM CST THU FEB 03 2011
AREAS AFFECTED...SWRN LA INTO E-CNTRL LA AND CNTRL MS
CONCERNING...WINTER MIXED PRECIPITATION
VALID 031858Z - 040000Z
MIXED PRECIPITATION TYPES ARE ANTICIPATED INTO THIS EVENING...WITH
AREAS OF FREEZING RAIN AND SLEET EXPECTED. FREEZING RAIN RATES COULD
REACH 0.05 TO 0.10 INCH PER 3 HOURS...ESPECIALLY ACROSS PORTIONS OF
CNTRL AND E-CNTRL MS AND ADJACENT AREAS OF SERN LOUISIANA DURING THE
MID/LATE AFTERNOON.
AN ELONGATED ZONE OF LOW/MID-LEVEL ISENTROPIC UPGLIDE WILL CONTINUE
TO SUPPORT AREAS OF PRECIPITATION ACROSS PORTIONS OF THE LOWER MS
VALLEY THROUGH THIS EVENING. THE 16Z RUN OF THE EXPERIMENTAL HRRR
DEPICTS THE CURRENT DISTRIBUTION OF PRECIPITATION WELL...WITH THE
MORE CONCENTRATED/INTENSE ACTIVITY ACROSS SRN LA/MS SHIFTING NEWD
ACROSS CNTRL/E-CNTRL MS TOWARD KJAN AND KMEI THROUGH LATE AFTERNOON.
IN THIS REGION...RUC FORECAST SOUNDINGS INDICATE TEMPERATURES IN THE
ELEVATED WARM NOSE FROM 3-5C. THIS WILL ALLOW FOR ANY PRECIPITATION
ALOFT TO MELT BEFORE FREEZING AT THE SURFACE...WHERE WET-BULB
TEMPERATURES ARE EXPECTED TO REMAIN BELOW FREEZING. LIQUID-
EQUIVALENT RATES OF 0.05 TO 0.10 INCH PER 3 HOURS WILL BE A CONCERN
WITH THIS ACTIVITY. WHILE SOME MODEL GUIDANCE INDICATES
PRECIPITATION COULD CHANGE TO RAIN ACROSS PORTIONS OF SERN MS LATER
THIS EVENING...THE STRENGTH OF THE ANTECEDENT COLD AIR MASS COULD
PREVENT THIS FROM OCCURRING. FARTHER NORTH AND WEST...PRECIPITATION
COVERAGE AND INTENSITY IS EXPECTED TO BE SOMEWHAT LESS. THERMAL
PROFILES FROM THE RUC SUGGEST THE ELEVATED WARM LAYER WILL BE COOLER
IN THIS REGION WITH MORE OF A SLEET/SNOW POTENTIAL.
..COHEN/PETERS.. 02/03/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BMX...MOB...JAN...LIX...LCH...SHV...
LAT...LON 30869348 31739263 32469125 33089018 33338864 32448835
31398879 30609067 30289219 30249320 30869348Nearby
Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Louisiana, 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.