SPC Severe Thunderstorm Watch 279

WW 279 SEVERE TSTM CO NE SD WY 172110Z - 180500Z
      
WW 0279 Image

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 279
NWS Storm Prediction Center Norman OK
310 PM MDT Tue Jul 17 2018

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Northeast Colorado
  Western Nebraska
  Southwest South Dakota
  Eastern Wyoming

* Effective this Tuesday afternoon and evening from 310 PM until
  1100 PM MDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible
  A tornado or two possible

SUMMARY...Relatively isolated strong to severe thunderstorms at
mid-afternoon should gradually increase in coverage and intensity
through late afternoon and early evening within an increasingly
unstable air mass across the High Plains. A relatively moist air
mass and strengthening winds aloft will support some supercells
capable of large hail. Storms may eventually cluster into a
semi-organized system capable of localized wind damage later this
evening.

The severe thunderstorm watch area is approximately along and 80
statute miles east and west of a line from 40 miles northeast of
Gillette WY to 25 miles south of Akron CO. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU9).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 278...

AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
28025.

...Guyer

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SPC Severe Thunderstorm Watch 279 Status Reports

WW 0279 Status Updates
      
WW 0279 Status Image

STATUS REPORT ON WW 279

THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.

FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1069

..SQUITIERI..07/18/18

ATTN...WFO...BOU...GLD...CYS...LBF...UNR...


STATUS REPORT FOR WS 279 

SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS 

COC075-087-095-115-121-123-125-180140-

CO 
.    COLORADO COUNTIES INCLUDED ARE

LOGAN                MORGAN              PHILLIPS            
SEDGWICK             WASHINGTON          WELD                
YUMA                 


NEC007-013-033-045-049-069-105-123-157-161-165-180140-

NE 
.    NEBRASKA COUNTIES INCLUDED ARE

BANNER               BOX BUTTE           CHEYENNE            
DAWES                DEUEL               GARDEN              
KIMBALL              MORRILL             SCOTTS BLUFF        
SHERIDAN             SIOUX               


SDC019-033-047-081-102-103-180140-

SD 
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SPC Severe Thunderstorm Watch 278 Status Reports

WW 0278 Status Updates
      
WW 0278 Status Image

STATUS REPORT ON WW 278

SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SSW BOS
TO 25 ENE BOS TO 35 ENE BOS.

REMAINING VALID PORTION OF WW 278 MAY BE ALLOWED TO EXPIRE AT 17/23Z.

..KERR..07/17/18

ATTN...WFO...BOX...ALY...GYX...


STATUS REPORT FOR WS 278 

SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS 

MAC005-021-023-172300-

MA 
.    MASSACHUSETTS COUNTIES INCLUDED ARE

BRISTOL              NORFOLK             PLYMOUTH            


ANZ251-172300-

CW 

.    ADJACENT COASTAL WATERS INCLUDED ARE

MASSACHUSETTS BAY AND IPSWICH BAY 

THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY.  PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.

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SPC MD 1069

MD 1069 CONCERNING SEVERE THUNDERSTORM WATCH 279... FOR NORTHEAST WYOMING...FAR NORTHWEST NEBRASKA...WESTERN SOUTH DAKOTA
MD 1069 Image


Mesoscale Discussion 1069
NWS Storm Prediction Center Norman OK
0649 PM CDT Tue Jul 17 2018

Areas affected...Northeast Wyoming...far northwest
Nebraska...Western South Dakota

Concerning...Severe Thunderstorm Watch 279...

Valid 172349Z - 180145Z

The severe weather threat for Severe Thunderstorm Watch 279
continues.

SUMMARY...Isolated severe threat continues, with a slow weakening
trend noted. Marginally severe hail/wind remain the primary threats.

DISCUSSION...Earlier discrete storms along the Wyoming/Montana
border have begun to grow upscale into a more loosely organized
convective complex. These storms are expected to progress slowly
eastward/southeastward over the next few hours, aided by modest
larger scale lift associated with an approaching mid-level shortwave
trough and left-exit region of a weak upper-level jet streak. 

An outflow boundary is oriented roughly along a line from CUT to
ECS, with more stable air located just to the east of the boundary.
Storms that may traverse the boundary have the best chance at
ingesting more buoyant surface based parcels and maintaining their
intensity, perhaps producing marginally severe hail/wind. As
nocturnal cooling sets in, the boundary layer will stabilize and any
remaining storms are expected to decrease in intensity, given that
effective bulk shear remains non-supportive of updraft organization.
 
Elsewhere across Severe Thunderstorm Watch 0279, the trend has been
for storms to weaken, and this trend will likely continue for the
remainder of the evening.

..Squitieri.. 07/17/2018

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

ATTN...WFO...LBF...UNR...GLD...BOU...CYS...BYZ...

LAT...LON   42490602 43350601 44790595 45000584 45160559 45250499
            45160396 45090355 44730274 44270230 43840216 43640211
            42690205 42130209 41220205 40160209 39640212 39550251
            39590339 39650360 40010383 40120456 40290484 40810480
            41080497 42450525 42550553 42550589 42490602 

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SPC Jul 18, 2018 0100 UTC Day 1 Convective Outlook

SPC 0100Z Day 1 Outlook
      
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0756 PM CDT Tue Jul 17 2018

Valid 180100Z - 181200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN AND CENTRAL HIGH PLAINS...

...SUMMARY...
A few strong to severe thunderstorms with hail and wind remain
possible across parts of the northern High Plains into the Central
Plains through evening. Isolated strong storms may persist across
Maryland and northern Virginia through early evening with strong
wind gusts.

...Central/Northern Plains...
Scattered storms persist this evening across the northern and
central high Plains aided by moist southeasterly surface winds and a
low-amplitude shortwave trough moving across WY.  The most intense
areas of ongoing storms were across the Black Hills as of 01Z, with
a few strong storms over northeastern CO as well. 00Z soundings
across the region show marginal instability profiles, but lack of
any appreciable capping inversion suggests storms will persist for
several more hours as they propagate slowly southeastward, supported
by a increasing low-level jet. Additional sporadic development is
possible this evening across KS and OK where the most unstable air
mass resides. Scattered cells were already developing over southwest
KS in proximity to a hot air mass to the south.

...MD...northern VA...
A few strong storms persist early this evening along a cold front
across parts of MD and northern VA. 00Z soundings continue to show
moist, unstable profiles immediately ahead of these storms with
generally weak shear. However, a relatively cool air mass from
earlier outflow exists across parts of the Delmarva, suggesting
storms will diminish.

..Jewell.. 07/18/2018

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