Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


 
USA.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

Mesoscale Discussion 1955
< Previous MD         Next MD >
MD 1955 graphic

   Mesoscale Discussion 1955
   NWS Storm Prediction Center Norman OK
   1228 PM CDT Wed Sep 11 2019

   Areas affected...eastern WY into far western NE and north-central CO

   Concerning...Severe potential...Watch likely 

   Valid 111728Z - 111930Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Thunderstorms will increase in coverage and intensity over
   the next couple of hours. All severe hazards will be possible (large
   hail, damaging gusts and a couple of tornadoes) and a watch is
   expected in the next 1-2 hours.

   DISCUSSION...Modest destabilization is occurring across eastern
   WY/CO into the central Plains at midday. Low level stratus over far
   eastern WY into the NE Panhandle and northeast CO is slowly eroding
   and this trend is expected to continue through the afternoon.
   However, this cloud cover may limit convective initiation/eastward
   progression of thunderstorms until later this afternoon into the
   evening. 

   In the near-term, a more confined severe threat is expected mainly
   across eastern WY and perhaps into far north-central CO. Stronger
   forcing for ascent associated with a shortwave impulse lifting
   northeast across the Great Basin is now ejecting into western
   WY/northwest CO as indicated by WV imagery and an increase in
   thunderstorms developing across the higher terrain of south-central
   WY into far north-central CO. As stronger heating occurs across this
   region in broken mid/upper level cloudiness, MLCAPE should increase
   to 500-1500 J/kg by 19-20z. 12z regional RAOBs show steep midlevel
   lapse rates across the region ranging from 7.5-8.5 C/km in the
   presence of strong shear supportive of rotating updrafts. This will
   result in a threat for large (some greater than 2 inches) hail. Dew
   points across eastern WY are generally in the low to mid 50s with
   higher quality moisture existing well to the east. Nevertheless,
   backed low level winds and low LCLs for this region could be
   sufficient for a couple of tornadoes, mainly across southeast WY.
   Fast storm motion also will aid in damaging wind potential. Given a
   more meridional and unidirectional component to vertical winds above
   around 2 km, some bowing segments/clusters also will be possible in
   addition to more discrete convection. A watch will likely be needed
   for portions of the MCD area in the next 1-2 hours.

   ..Leitman/Hart.. 09/11/2019

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

   ATTN...WFO...UNR...BOU...CYS...BYZ...RIW...

   LAT...LON   41360335 42380329 43020351 43740394 44730481 44920559
               44680618 42420709 41640726 41100690 40580619 40440520
               40570425 41360335 

Top/All Mesoscale Discussions/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified: September 11, 2019
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities