Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 250551
SWODY2
SPC AC 250550

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1250 AM CDT WED MAY 25 2016

VALID 261200Z - 271200Z

...THERE IS AN ENH RISK OF SVR TSTMS FROM SRN NEB AND KS SWD INTO
WRN OK...

...THERE IS A SLGT RISK OF SVR TSTMS FOR A LARGE PORTION OF THE
CNTRL-SRN PLAINS INTO IA/MO...

...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE SLIGHT RISK AND
EWD INTO THE SWRN GREAT LAKES...

...SUMMARY...
SEVERE THUNDERSTORMS WITH LARGE HAIL...WIND DAMAGE AND A FEW
TORNADOES WILL BE POSSIBLE THURSDAY AFTERNOON AND EVENING ACROSS
PARTS OF THE SOUTHERN AND CENTRAL PLAINS NORTHEASTWARD INTO THE
LOWER TO MID MISSOURI VALLEY. OTHER MARGINALLY SEVERE STORMS WITH
HAIL AND STRONG WIND GUSTS MAY OCCUR ACROSS PARTS OF THE MID TO
UPPER MISSISSIPPI VALLEY AND SOUTHWESTERN GREAT LAKES REGION.

...SYNOPSIS...
A LARGE-SCALE UPPER TROUGH OVER THE FOUR CORNERS WILL SHIFT EWD
ACROSS THE SRN ROCKIES AND INTO THE HIGH PLAINS.  A LEAD DISTURBANCE
WILL MOVE ACROSS TX DURING THE DAY AND INTO THE ARKLATEX WITH THE
PRIMARY BELT OF STRONGER FLOW H5 FLOW REMAINING NEAR THE DRYLINE WWD
INTO W TX AND ERN NM DURING THE DIURNAL HEATING CYCLE.  A SURFACE
LOW INVOF SWRN KS WILL MOVE LITTLE DURING THE PERIOD WITH AN
ATTENDANT NORTH-SOUTH DRYLINE.  A FRONT WILL EXTEND NNEWD FROM THE
CNTRL HIGH PLAINS INTO THE UPPER MS VALLEY.

...CNTRL KS/OK/TX...
SLY LOW-LEVEL FLOW AND RICH MOISTURE WILL CONTINUE TO STREAM NWD
INTO THE SRN-CNTRL PLAINS.  FAIRLY GOOD AGREEMENT AMONGST MODEL
GUIDANCE INDICATES A LOW-AMPLITUDE DISTURBANCE WILL MOVE ACROSS
S-CNTRL INTO ERN PARTS OF TX DURING THE MORNING AND MIDDAY HOURS
WITH MODULATIONS OF THE WIND PROFILE AS FAR N AS OK DURING THE DAY.
A DEVELOPING CLUSTER OF SHOWERS/STORMS WILL SEEMINGLY EXPAND EARLY
ACROSS CNTRL-ERN TX AMIDST A BUOYANT AIRMASS WITH ADEQUATE SHEAR FOR
SOME STRONG TO LOCALLY SEVERE STORMS CAPABLE PRIMARILY OF AN ISOLD
HAIL/WIND-DAMAGE THREAT.

THE FOCUS FOR MORE INTENSE THUNDERSTORM DEVELOPMENT WILL SHIFT
FARTHER W NEAR AND E OF THE DRYLINE BY AFTERNOON.  INCREASING
FORCING FOR ASCENT OVERSPREADING A DESTABILIZING/MOIST BOUNDARY
LAYER /LOWEST 100-MB MEAN MIXING RATIOS 13-16 G PER KG/ WILL
CONTRIBUTE TO MODERATE TO VERY STRONG BUOYANCY /1500-3500 J PER KG
MLCAPE/.  THE WIND PROFILE ASSOCIATED WITH THE LEAD DISTURBANCE AND
UPPER-LEVEL BACKING ARE RESULTING IN SOME PROGGED WEAKNESSES THAT
WILL PROBABLY PLAY A ROLE IN STORM LONGEVITY/INTENSITY.
NONETHELESS...A WIND PROFILE SUPPORTIVE OF SEVERE STORMS /INCLUDING
SUPERCELLS/ WILL FACILITATE THE DEVELOPMENT OF A LARGE TO VERY
LARGE-HAIL THREAT...ISOLD SEVERE GUSTS...AND THE POSSIBILITY FOR A
COUPLE OF TORNADOES TOWARDS EVENING AS THE LLJ STRENGTHENS AND
HODOGRAPHS ENLARGE.  A STORM CLUSTER OR TWO COULD EVOLVE PERHAPS
NEAR THE RED RIVER OVERNIGHT WITH A LINGERING HAIL/WIND THREAT INTO
THE EARLY HOURS FRIDAY.

...CNTRL PLAINS INTO THE MIDWEST...
A WEAKENING CLUSTER OF TSTMS MAY BE ONGOING THURSDAY MORNING ACROSS
THE LOWER MO VALLEY WITH IT PERHAPS POSING AN ISOLD STRONG TO SEVERE
RISK. AN OUTFLOW BOUNDARY FROM THIS ACTIVITY MAY ARC WWD INTO THE
CNTRL PLAINS WHERE STRONG HEATING IS FORECAST TO STRONGLY
DESTABILIZE THE BOUNDARY LAYER.  ELY MOIST UPSLOPE FLOW N OF THE LOW
IN THE CNTRL HIGH PLAINS AND CLOSER PROXIMITY TO H5 HEIGHT FALLS /30
M PER 12 HR/ WILL PROBABLY LEAD TO ISOLD-SCTD STORMS DEVELOPING BY
EARLY AFTERNOON OVER ERN CO AND DEVELOPING NEWD NEAR THE FRONT.
STEEP LAPSE RATES COUPLED WITH A VEERING/STRENGTHENING WIND PROFILE
WITH HEIGHT WILL FAVOR STORM ORGANIZATION AND ROTATION WITH THE
STRONGER UPDRAFTS.  RELATIVELY BACKED LOW-LEVEL FLOW NE OF THE
SURFACE LOW MAY YIELD A PERIOD WHEN SRH INCREASES INTO THE 200-300
M2/S2 RANGE WITH A QUASI-DISCRETE MODE AND SOME LOW-LEVEL
MESOCYCLONE ENHANCEMENT PRIOR TO THE TERMINUS OF A SLY LLJ BECOMING
FOCUSED OVER THE CNTRL PLAINS DURING THE EVENING AND LIKELY LEADING
TO UPSCALE GROWTH OF A TSTM CLUSTER NEAR THE NEB/KS BORDER.  AS THE
LLJ STRENGTHENS AND VEERS DURING THE EVENING/OVERNIGHT...THIS
ACTIVITY WILL SHIFT EWD INTO THE LOWER MO VALLEY WITH AN ATTENDANT
RISK FOR ISOLD LARGE HAIL/DMGG WINDS.  STRONG TO LOCALLY SEVERE
STORMS MAY DEVELOP AS FAR E AS THE MID MS VALLEY OVERNIGHT THURSDAY.

..SMITH.. 05/25/2016

$$



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