Severe Weather Outlook for June 19, 2013

This page has information on possible thunderstorms, high winds, or tornadoes for the next 24 hours as provided by the Weather Service Storm Prediction Center. You can also view the possibility of severe weather for the next two days. The map and discussion are updated several times a day.

Refer to the text discussion below the map for descriptions of possible severe weather threats.

Hazardous Weather Forecast Maps:

Severe Weather Discussion:

494 
ACUS01 KWNS 191932
SWODY1
SPC AC 191930

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0230 PM CDT WED JUN 19 2013

VALID 192000Z - 201200Z

...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN INTO TONIGHT FOR
PORTIONS OF CENTRAL/NORTHERN MONTANA INTO NORTHWESTERN NORTH
DAKOTA...

...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN AND EVE ACROSS
PARTS OF THE SOUTHERN PLAINS...

...20Z OUTLOOK UPDATE...PLAINS...
PROBABILISTIC AND CATEGORICAL SEVERE OUTLOOK LINES HAVE BEEN
ADJUSTED ACROSS PARTS OF THE SOUTHERN PLAINS TO ACCOUNT FOR THE
ONGOING STORM CLUSTER AND ASSOCIATED CONVECTIVE OUTFLOW BOUNDARY
ADVANCING SOUTHWARD THROUGH PARTS OF NORTHWEST TEXAS AND THE TEXAS
SOUTH PLAINS.  STORMS MAY STILL INTENSIFY DURING THE NEXT FEW HOURS
IN A NARROW CORRIDOR OF STRONGER HEATING AHEAD OF IT...INTO PORTIONS
OF THE EDWARDS PLATEAU.  OTHERWISE...THE OUTFLOW BOUNDARY TRAILING
TO THE WEST/NORTHWEST...INTO PARTS OF EASTERN NEW MEXICO MAY REMAIN
A FOCUS FOR A RELATIVELY HIGHER CONCENTRATION OF NEW...
STRONG/SEVERE STORM DEVELOPMENT LATE THIS AFTERNOON AND EVENING. 
STORM DEVELOPMENT THROUGH THE REMAINDER OF THE PLAINS...NORTHWARD
ACROSS EASTERN COLORADO/WESTERN KANSAS THROUGH THE BLACK HILLS
AREA...WHILE NOT OUT OF THE QUESTION...AND WITH AT LEAST SOME RISK
FOR SEVERE WEATHER...MAY REMAIN SOMEWHAT SPARSE IN COVERAGE...AS
VERY WARM ELEVATED MIXED LAYER AIR SLOWLY ADVECTS EAST OF THE
ROCKIES THROUGH MUCH OF THE PLAINS.

..KERR.. 06/19/2013

.PREV DISCUSSION... /ISSUED 1130 AM CDT WED JUN 19 2013/

...MT/NW ND THROUGH TONIGHT...
A DEEP CLOSED LOW OVER THE PAC NW WILL PROGRESS INLAND AS A
PRONOUNCED SHORTWAVE TROUGH OVER NV ROTATES NEWD TO ID BY THIS
EVENING AND MT OVERNIGHT.  AT THE SURFACE...STRONG CYCLOGENESIS IS
EXPECTED IN THE LEE OF THE NRN ROCKIES MOUNTAINS ACROSS S CENTRAL MT
AND NRN WY...IN ADVANCE OF THE EJECTING SHORTWAVE TROUGH.  THE
PRESSURE FALLS ACROSS MT AND THE REST OF THE NRN HIGH PLAINS WILL
INDUCE STRONG SELY LOW-LEVEL FLOW INTO MT THROUGH TONIGHT...IN
ADVANCE OF THE SURFACE LOW AND A COLD FRONT WHICH WILL CROSS WY/MT
IN ASSOCIATION WITH THE MIDLEVEL TROUGH.  REGIONAL 12Z SOUNDINGS
REVEALED RATHER MODEST BOUNDARY LAYER MOISTURE FROM NEB TO MT WITH
100 MB MEAN MIXING RATIOS OF 8-10 G/KG...WHICH TRANSLATES TO
DEWPOINTS MOSTLY IN THE MID-UPPER 50S AT ABOUT 2500 FT MSL.  THE
ONLY LIKELY INCREASE IN MOISTURE TODAY INTO MT WILL BE THROUGH
EVAPOTRANSPIRATION...GIVEN SIMILAR MOISTURE OBSERVATIONS UPSTREAM
ACROSS THE CENTRAL/NRN HIGH PLAINS.  THUS...MODERATE INSTABILITY
/MLCAPE OF 1500-2500 J PER KG/ IS EXPECTED BY MID-LATE AFTERNOON AS
SURFACE TEMPERATURES WARM INTO THE 85-90 F RANGE ACROSS CENTRAL/ERN
MT...BENEATH 8-9 C/KM MIDLEVEL LAPSE RATES.

THUNDERSTORM DEVELOPMENT IS FIRST EXPECTED BY EARLY-MID AFTERNOON
OVER THE HIGHER TERRAIN OF SW/S CENTRAL MT...AND THIS CONVECTION
WILL SPREAD NNEWD TOWARD N CENTRAL MT THIS EVENING.  SUPERCELLS WITH
LARGE HAIL WILL BE POSSIBLE INITIALLY...THOUGH UPSCALE GROWTH INTO
CLUSTERS/LINE SEGMENTS APPEARS LIKELY THIS EVENING.  THE UPSCALE
GROWTH WILL BE DRIVEN BY STORM/OUTFLOW INTERACTIONS IN AN
ENVIRONMENT WITH RATHER MODEST DEEP-LAYER SHEAR IN THE WARM SECTOR
/EFFECTIVE BULK SHEAR OF 25-30 KT DUE TO BACKED FLOW ALOFT/...AS
WELL AS TEMPERATURE-DEWPOINT SPREADS NEAR 30 F AND STRONG LINEAR
FORCING FOR ASCENT ALONG THE SURGING COLD FRONT.  THE GREATER RISK
FOR MORE PERSISTENT SUPERCELLS...WITH AN ACCOMPANYING RISK FOR MORE
SIGNIFICANT HAIL AND PERHAPS A COUPLE OF TORNADOES...WILL BE ALONG
AND ON THE IMMEDIATE COOL SIDE OF THE BAROCLINIC ZONE ACROSS CENTRAL
MT /FROM ABOUT HVR-LWT-GTF-CTB TO CTB/...WHERE LOW-LEVEL SHEAR AND
MOISTURE WILL BE MAXIMIZED.  OTHERWISE...EXPECT CONVECTION TO EXPAND
EWD OVERNIGHT ALONG THE COLD FRONT INTO ERN MT...WITH THE POTENTIAL
FOR ISOLATED DAMAGING WINDS/HAIL.

...CENTRAL/SRN HIGH PLAINS THROUGH TONIGHT...
AN MCS CONTINUES TO MOVE SEWD ACROSS THE SE TX PANHANDLE INTO NW TX
AS OF 16Z.  THERE WILL BE SOME POTENTIAL FOR RE-INVIGORATION OF THE
STORMS ALONG THE LEADING EDGE OF THE COLD POOL THIS AFTERNOON AS THE
BOUNDARY LAYER DESTABILIZES.  ALSO...ISOLATED THUNDERSTORM
DEVELOPMENT WILL BE POSSIBLE FARTHER W ALONG THE OUTFLOW BOUNDARY
INTO W CENTRAL TX/E CENTRAL NM.  FARTHER N...THE FOCUS FOR STORM
INITIATION IS UNCERTAIN GIVEN THE TENDENCY FOR SLOW HEIGHT RISES
ACROSS THE HIGH PLAINS.  SURFACE HEATING/MIXING ALONG THE EXTENSIVE
LEE TROUGH COULD SUPPORT ISOLATED THUNDERSTORM DEVELOPMENT FOR A FEW
HOURS LATE THIS AFTERNOON/EVENING FROM ERN CO/WRN KS SWD INTO NE
NM/NW TX PANHANDLE IN THE ZONE OF INCREASING LOW-LEVEL MOISTURE...TO
THE W-NW OF THE MORNING TX PANHANDLE MCS.  THIS ZONE WILL HAVE
SUFFICIENT INSTABILITY AND VERTICAL SHEAR FOR SUPERCELLS...WITH A
RISK FOR AT LEAST ISOLATED LARGE HAIL AND DAMAGING WINDS.  FARTHER
N...THE FOCUS FOR STORM DEVELOPMENT IS LESS CLEAR...OTHER THAN THE
OROGRAPHIC INFLUENCE OF THE BLACK HILLS.