Jump to content
  • Member Statistics

    16,800
    Total Members
    7,904
    Most Online
    Doug747
    Newest Member
    Doug747
    Joined

General severe weather discussion


Quincy
 Share

Recommended Posts

this storm is quite far from radar stations

 

Quote

* At 409 PM MDT, a confirmed large and extremely dangerous tornado
  was located 6 miles northeast of Sterling, moving northeast at 40
  mph.

  This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!

  HAZARD...Damaging tornado.

  SOURCE...Weather spotters confirmed tornado.

 

Link to comment
Share on other sites

The models generally have a low on the high plains on Wednesday evening, with 60-70F dew points in the warm sector. It seems that 0-6km shear and storm-relative helicity may be increasing strongly in the evening hours. I think we will have at least some severe weather in the central plains.

ItDSBKP.jpg

  • Like 2
Link to comment
Share on other sites

NW of Boise City, OK

Braydon Morisseau on Twitter: "Expanded and sounds like a large tornado NW of Boise City, Oklahoma #okwx 9:28PM @PrairieChasers @RadarOmega_WX https://t.co/IZH9S1YKrs" / Twitter

Image

EDIT: Seems like some chasers are convinced it was a scud bomb (either this image or other reported tornadoes in the area). Guess we'll find out later.

Link to comment
Share on other sites

I think in Colorado it was a noteworthy tornado. Once it got into the western Oklahoma panhandle, it was a lot less conclusive. It may have touched down a few brief times over the border, but I think the main deal was earlier. Terrain was a pain, for visibility and navigation. 

  • Like 1
Link to comment
Share on other sites

  • 2 weeks later...

Looks like June 6, 2020 (the 0100z SPC OTLK technically) was last time MOD risk was issued in the Dakotas/Montana... June 18, 2018 looks like the one before that

No MOD risk issued on the 1300 SPC OTLK... but disco mentions potential wind driven one could be issued later

Link to comment
Share on other sites

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1149 AM CDT Thu Jun 10 2021

   Valid 101630Z - 111200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE
   WESTERN DAKOTAS...

   ...SUMMARY...
   Scattered severe thunderstorms are likely late this afternoon and
   tonight across much of the northern and central Plains, especially
   across eastern Montana, the Dakotas, and Nebraska. All severe
   hazards are possible, including very large hail, wind gusts above 70
   mph, and a few tornadoes.

   ...Northern/central Plains including Dakotas/Nebraska/E Montana...
   An active severe-weather day is expected across the region late this
   afternoon and tonight and have upgraded parts of the western Dakotas
   to a categorical Moderate Risk, with much of this regional risk
   expected to persist well through the late-night hours.

   12Z upper-air analysis/soundings essentially sampled near-record
   moisture content by early/mid-June standards across the High Plains
   in terms of mean mixing ratios/850mb dewpoints, including locations
   such as Dodge City/North Platte/Rapid City/Bismarck/Glasgow Montana,
   although mid-level/700 mb temperatures were notably warm
   (near-record values) at these locations as well.

   Thunderstorms should develop initially this afternoon into early
   evening near the surface low and adjoining frontal segments over
   eastern Montana and the western Dakotas. Supercells capable of all
   hazards (tornado, large to giant hail, severe wind gusts) are
   expected in the first few hours of the convective cycle. This should
   be followed by a transition to one or more organized convective
   complexes with a dominant destructive-wind hazard, with isolated
   severe hail and possibly some tornado threat. During and after that
   transition, very damaging gusts to hurricane force may be observed
   through the evening and possibly the early overnight hours.

   Very steep mid-level lapse rates will overlie a corridor of
   moist/theta-e advection and diurnal heating south of the warm front
   and east of the low/cold front. This will contribute to MLCAPE
   strengthening into the 2000-3000 J/kg range (locally higher), amidst
   intensifying deep shear (effective-shear magnitudes reaching 35-50
   kt). Low-level shear should be maximized along the warm front and
   east of the surface low across eastern Montana and western North
   Dakota.

   Farther south across portions of South Dakota/Nebraska and perhaps
   northeast Colorado, high-based supercells should form late this
   afternoon/early evening near the dryline/lee trough, offering
   significant hail and severe gusts. However, this activity may evolve
   upscale more quickly to a QLCS configuration with a dominant wind
   threat. Deep, well-mixed sub-cloud layers will support maintenance
   of both severe hail and gusts to the surface during earlier,
   relatively discrete stages, but also, foster quick cold-pool
   aggregations and rapid expansion. Forced ascent of a foregoing
   boundary layer containing 60s to near 70 F surface dew points, with
   MLCAPE commonly remaining above 2000 J/kg even well after sunset,
   will help to drive the severe-wind threat southeastward over much of
   Nebraska tonight.
Link to comment
Share on other sites

ND/MT/S SK target looks pretty ripe this afternoon with mid-upper 60s dewpoints near the triple point, an arcing dryline, strong ESE surface flow and SE flow at 850 mb pushing 50 kts. Upscale growth would be the main concern, but I'd imagine there will be at least a couple tornadoes in that area later. Further south, moisture is overperforming the HRRR (no surprise) and there's certainly an opportunity for initiation in WY/NE later as a subtle shortwave ejects from the Rockies, although 700 mb temps are quite warm. Certainly a lower probability threat than further north, but could yield something pretty spectacular if it works out.

Link to comment
Share on other sites

mcd0908.gif

 

Mesoscale Discussion 0908
   NWS Storm Prediction Center Norman OK
   0256 PM CDT Thu Jun 10 2021

   Areas affected...far northeast MT...western ND

   Concerning...Severe potential...Tornado Watch likely 

   Valid 101956Z - 102130Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Convective initiation is expected between 20-21 UTC along
   the dryline over eastern MN near the ND border.  Explosive growth
   into significant-severe producing supercells is forecast late this
   afternoon into the early evening.

   DISCUSSION...Visible-satellite imagery shows a swelling band of
   agitated cumulus along the dryline over far eastern MT near Sydney. 
   Temperatures immediately east of the dryline have warmed into the
   lower 80s with a deepening boundary layer featuring low to mid 60s
   deg F dewpoints.  The 18 UTC Glasgow, MT raob showed a very steep
   700-500 mb lapse rate (8.6 deg C/km).  Modifying the raob for 19 UTC
   surface conditions east of the dryline near the ND/MT border (i.e.,
   Sydney, MT) yielded 3300 J/kg MLCAPE with very little convective
   inhibition remaining.  As the cap erodes, expecting explosive
   updraft growth quickly evolving into a few discrete supercells. 
   Giant hail (3+ inches in diameter) is possible with the stronger
   storms as the organize and move northeast into a less deeply mixed
   and more moisture rich environment near the warm front.  Supercell
   tornadoes will be possible in vicinity of the warm front, in
   addition to the hail/severe gust hazard.  Other isolated storms are
   forecast to eventually develop southward along the dryline into
   parts of southwest ND and northwest SD.  Large to giant hail will be
   the primary hazard with these storms before additional thunderstorm
   development into a severe squall line evolves later this evening.

   ..Smith/Guyer.. 06/10/2021

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

   ATTN...WFO...BIS...UNR...BYZ...GGW...
Link to comment
Share on other sites

1 minute ago, yoda said:

mcd0908.gif

 

Mesoscale Discussion 0908
   NWS Storm Prediction Center Norman OK
   0256 PM CDT Thu Jun 10 2021

   Areas affected...far northeast MT...western ND

   Concerning...Severe potential...Tornado Watch likely 

   Valid 101956Z - 102130Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Convective initiation is expected between 20-21 UTC along
   the dryline over eastern MN near the ND border.  Explosive growth
   into significant-severe producing supercells is forecast late this
   afternoon into the early evening.

   DISCUSSION...Visible-satellite imagery shows a swelling band of
   agitated cumulus along the dryline over far eastern MT near Sydney. 
   Temperatures immediately east of the dryline have warmed into the
   lower 80s with a deepening boundary layer featuring low to mid 60s
   deg F dewpoints.  The 18 UTC Glasgow, MT raob showed a very steep
   700-500 mb lapse rate (8.6 deg C/km).  Modifying the raob for 19 UTC
   surface conditions east of the dryline near the ND/MT border (i.e.,
   Sydney, MT) yielded 3300 J/kg MLCAPE with very little convective
   inhibition remaining.  As the cap erodes, expecting explosive
   updraft growth quickly evolving into a few discrete supercells. 
   Giant hail (3+ inches in diameter) is possible with the stronger
   storms as the organize and move northeast into a less deeply mixed
   and more moisture rich environment near the warm front.  Supercell
   tornadoes will be possible in vicinity of the warm front, in
   addition to the hail/severe gust hazard.  Other isolated storms are
   forecast to eventually develop southward along the dryline into
   parts of southwest ND and northwest SD.  Large to giant hail will be
   the primary hazard with these storms before additional thunderstorm
   development into a severe squall line evolves later this evening.

   ..Smith/Guyer.. 06/10/2021

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

   ATTN...WFO...BIS...UNR...BYZ...GGW...

I think they meant "a few supercells evolving into upscale growth"

 

Link to comment
Share on other sites

Wow... 80/80 probs on hail.  50/30 tor probs

URGENT - IMMEDIATE BROADCAST REQUESTED
   Tornado Watch Number 251
   NWS Storm Prediction Center Norman OK
   225 PM MDT Thu Jun 10 2021

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     Northeast Montana
     Western North Dakota

   * Effective this Thursday afternoon and evening from 225 PM until
     900 PM MDT.

   * Primary threats include...
     A few tornadoes and a couple intense tornadoes possible
     Widespread large hail and scattered very large hail events to 4
       inches in diameter likely
     Scattered damaging wind gusts to 70 mph likely

   SUMMARY...Intense thunderstorms including supercells will likely
   rapid develop through mid/late afternoon from east-central/northeast
   Montana into western South Dakota. Of greatest concern as far as
   intense supercells and a tornado risk will be those storms occurring
   near a west-east warm front across the region, where low-level
   moisture/shear will be maximized. A strong tornado is possible.

   The tornado watch area is approximately along and 80 statute miles
   north and south of a line from 10 miles north northwest of Wolf
   Point MT to 70 miles east southeast of Williston ND. For a complete
   depiction of the watch see the associated watch outline update
   (WOUS64 KWNS WOU1).
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...