Mesoscale Discussion 73

Issued

Jan 18, 2017, 11:56 PM CST (05:56 UTC)

Expired

Jan 19, 2017, 2:00 AM CST

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

20%

Counties Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, Evangeline Parish, LA, Jefferson Davis Parish, LA, Pointe Coupee Parish, LA, Saint Landry Parish, LA, Tensas Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Jefferson County, MS, Lincoln County, MS, Wilkinson County, MS

The Ft Polk radar (KPOE), 115 km from the middle of the area, began a volume at 06:00 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.

926 
ACUS11 KWNS 190556
SWOMCD
SPC MCD 190556 
MSZ000-LAZ000-190800-

Mesoscale Discussion 0073
NWS Storm Prediction Center Norman OK
1156 PM CST Wed Jan 18 2017

Areas affected...southwest through central Louisiana into southwest
Mississippi

Concerning...Severe potential...Watch unlikely 

Valid 190556Z - 190800Z

Probability of Watch Issuance...20 percent

SUMMARY...Threat for a couple instances of damaging wind and a brief
tornado will exist into the early morning from southwest through
central Louisiana into southwest Mississippi. Threat does not appear
sufficient for a WW, but area will continue to be monitored.

DISCUSSION...Some increase in thunderstorm organization and coverage
has been recently observed over southern LA into the northwest Gulf.
Uptick in convection appears to be in association to a modest
increase in the southwesterly low-level jet which will persist into
the morning hours in response to an upstream impulse. The marginal
thermodynamic environment with weak lapse rates and MLCAPE below 500
J/kg will remain the primary limiting factor. Moreover, while some
increase in vertical shear will occur, low-level hodograph size is
not expected to become exceptionally large. Nevertheless, the
kinematic environment will be sufficient for storms to develop at
least marginal supercell structures, especially as they move
northeast and interact with the stationary boundary across
south-central LA into southwest MS.

..Dial/Edwards.. 01/19/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...JAN...LIX...LCH...SHV...

LAT...LON   30429318 31799182 32469055 31839014 31189065 30629162
            29719304 30429318

Mesoscale Discussions in Louisiana, 2017Mesoscale Discussions in Mississippi, 2017Every mesoscale discussion in 2017

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.