Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS01 KWNS 221943
SWODY1
SPC AC 221942

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0242 PM CDT FRI MAY 22 2015

VALID 222000Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER ERN CO...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SWRN TX AND ERN NM...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS ERN CO...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE SRN PLAINS...

...SUMMARY...
ISOLATED SEVERE STORMS ARE POSSIBLE LATE THIS AFTERNOON ACROSS
SOUTHWEST TEXAS...AND A SMALL PART OF NORTHEAST COLORADO.
THUNDERSTORM COVERAGE INCLUDING SOME SEVERE THREAT WILL INCREASE
THROUGH TONIGHT ACROSS EASTERN NEW MEXICO AND SOUTHWEST TO WEST
TEXAS.

...SWRN TX...
STRONG HEATING HAS COMMENCED ACROSS SWRN TX WHERE BACKED SURFACE
WINDS WILL MAINTAIN PLENTY OF MOISTURE FOR SEVERE STORMS. A
SUPERCELL WIND PROFILE WILL FAVOR ISOLATED BUT INTENSE HAIL CORES
MAINLY ACROSS OPEN COUNTRY. A BRIEF TORNADO CANNOT BE RULED OUT AS
WELL. EWD EXTENT OF THE THREAT WILL BE MODULATED BY COOL/CAPPED
BOUNDARY LAYER. FOR MORE INFORMATION SEE MCD 717.

...ERN CO...
VISIBLE IMAGERY SHOWS CU INCREASING WITH TIME WITH HEATING NOW THAT
CLOUDS HAVE CLEARED. SHEAR PROFILES REMAIN FAVORABLE FOR SEVERE
STORMS AND CIN WILL CONTINUE TO BE ERODED THIS AFTERNOON. ISOLATED
SUPERCELLS APPEAR PROBABLE WITH LARGE HAIL THE PRIMARY THREAT.
FAVORABLE TIME OF DAY AS WELL AS LOW LEVEL TURNING OF THE WINDS WITH
HEIGHT MAY RESULT IN AN ISOLATED TORNADO AS WELL.

..JEWELL.. 05/22/2015

.PREV DISCUSSION... /ISSUED 1133 AM CDT FRI MAY 22 2015/

...SYNOPSIS...
AS AN INITIAL MID-LEVEL VORT MAX NOW OVER THE CENTRAL HIGH PLAINS
CONTINUES NNEWD TOWARD/INTO THE NRN PLAINS...THE LARGER/MAIN WRN
TROUGH WILL CONTINUE A SLOW ADVANCE ACROSS THE WRN STATES.
DOWNSTREAM...RIDGING CENTERED INVOF THE MS VALLEY WILL AMPLIFY WITH
TIME...AS A SECOND TROUGH OVER THE NERN U.S./ERN CANADA GRADUALLY
DEPARTS.

AT THE SURFACE...BROAD LOW PRESSURE IS PROGGED ACROSS THE
INTERMOUNTAIN W...WITH A LEE LOW EXPECTED TO RESIDE OVER ERN CO
DURING THE AFTERNOON AND A LEE TROUGH EXTENDING SWD ACROSS ERN NM.
FARTHER E...HIGH PRESSURE WILL PREVAIL ACROSS THE CENTRAL
STATES...WHILE A SECONDARY/REINFORCING COLD FRONT MOVES SEWD ACROSS
THE NERN STATES THROUGH THE PERIOD.

...FAR W TX AND NWD ACROSS ERN NM...
DIURNAL HEATING OF A RELATIVELY MOIST AIRMASS BACKED WNWWD TO FAR W
TX/SERN NM WILL RESULT IN MODERATE DESTABILIZATION DURING THE
AFTERNOON -- LIKELY SUFFICIENT FOR ISOLATED THUNDERSTORM DEVELOPMENT
OVER THE HIGHER TERRAIN.  WITH LOW-LEVEL SELYS BENEATH INCREASING
WSWLYS AT MID LEVELS...DEGREE OF VEERING/SHEAR WILL FAVOR
ROTATING/SUPERCELL EVOLUTION...WITH LARGE HAIL AND DAMAGING WINDS
ALONG WITH POSSIBLY A TORNADO OR TWO.  DURING THE
EVENING/OVERNIGHT...INCREASING HEIGHT FALLS ACROSS THE SRN PLAINS
AHEAD OF THE ADVANCING WRN SYSTEM SUGGEST AN INCREASE IN CONVECTION
OVER ERN NM WILL BE POSSIBLE...SPREADING WITH TIME INTO THE TX
PANHANDLE AND S PLAINS REGION.  THOUGH INSTABILITY WILL LIKELY BE
LIMITED...INCREASINGLY FAVORABLE SHEAR AHEAD OF THE ADVANCING TROUGH
SUGGESTS A FEW STRONGER STORMS WILL BE CAPABLE OF PRODUCING HAIL
AND/OR DAMAGING WINDS.

...NERN CO...
CLEARING IS OCCURRING FROM S-N ACROSS CO ATTM...AS THE VORT MAX
SHIFTS NWD/AWAY FROM THE AREA.  WHILE SHORT-WAVE RIDGING SHOULD
SUPPRESS CONVECTION IN THE NEAR TERM...HEATING/DESTABILIZATION
THROUGH THE AFTERNOON MAY SUPPORT ISOLATED STORM DEVELOPMENT --
AIDED BY SELY UPSLOPE FLOW JUST N OF THE SURFACE LOW -- AS
LARGER-SCALE HEIGHT FALLS OCCUR AHEAD OF THE MAIN UPPER SYSTEM.
WITH THE LOW-LEVEL SELYS ALSO CONTRIBUTING TO SUBSTANTIAL VEERING
WITH HEIGHT AS FLOW BECOMES WNWLY AT MID LEVELS...SHEAR SUPPORTIVE
OF ROTATING STORMS -- AND ATTENDANT RISKS FOR HAIL AND DAMAGING
WINDS ALONG WITH A TORNADO OR TWO REMAIN EVIDENT INTO THIS EVENING.




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