SPC MD 1529

MD 1529 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PORTIONS ERN CO…SERN WY…NEB PANHANDLE.


MESOSCALE DISCUSSION 1529
NWS STORM PREDICTION CENTER NORMAN OK
0221 PM CDT FRI JUL 26 2013

AREAS AFFECTED...PORTIONS ERN CO...SERN WY...NEB PANHANDLE.

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 261921Z - 262115Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...POTENTIAL FOR SVR TSTM DEVELOPMENT IS EXPECTED TO INCREASE
FROM LARAMIE RANGE SEWD ACROSS CYS RIDGE INTO NERN CO...NW OF
EXISTING CONVECTION.  TSTMS MOVING SSEWD ACROSS ERN CO ALSO MAY
PRODUCE ISOLATED STG-SVR GUSTS.

DISCUSSION...SFC MESOANALYSIS AND VIS IMAGERY INDICATE BAROCLINIC
BOUNDARY -- REINFORCED BY BOTH OUTFLOW AND EARLIER PERIOD OF
DIFFERENTIAL HEATING ALONG CLOUD-COVER EDGE -- FROM RAWLINS COUNTY
KS NWWD ACROSS WELD COUNTY CO AND INTO SERN WY NEAR CYS.
WELL-DEFINED ISALLOBARIC FALL AXIS TO ITS N...AND RELATED VEERING OF
POST-FRONTAL SFC WINDS TO ELY...INDICATE THIS BOUNDARY SHOULD
DECELERATE AS IT MOVES SWWD ACROSS NERN CO AND ERN WY...EXCEPT INVOF
NEWER CONVECTIVE OUTFLOW.

ISOLATED MULTICELL TSTM CLUSTER...APCHG I-70 BETWEEN LIC-ITR AS OF
19Z...DEVELOPED ALONG THAT BOUNDARY AND IS MOVING SSEWD ABOUT 20 KT.
ACTIVITY MAY ACCELERATE IF AGGREGATED COLD POOL CAN DEVELOP
SUFFICIENTLY TO INDUCE FORWARD-PROPAGATION AND FORCED ASCENT.  AIR
MASS IN PROJECTED PATH OF THIS CONVECTION IS CHARACTERIZED BY SFC
DEW POINTS MAINLY LOW 50S F.  STG DIABATIC SFC HEATING WILL BOOST
DEW POINT DEPRESSIONS...LEADING TO INVERTED-V THERMODYNAMIC PROFILES
IN SUBCLOUD LAYER AND LOCALLY ENHANCED SVR GUST POTENTIAL.
OUTFLOW-DOMINANCE ALSO SHOULD LEAD TO TSTM WEAKENING/DISSIPATION
WITHIN A FEW HOURS...ALTHOUGH ADDITIONAL/POORLY ORGANIZED
DEVELOPMENT MAY OCCUR ALONG THAT OUTFLOW.

MORE ORGANIZED POTENTIAL...INCLUDING AT LEAST MRGL SUPERCELL
RISK...MAY ARISE FROM CONVECTION FORMING OVER LARAMIE RANGE ATTM
AND/OR CYS RIDGE LATER THIS AFTN...AND MOVING SEWD TO SSEWD BEHIND
FRONT.  AFOREMENTIONED ELYS WILL CONTINUE TO ADVECT MOISTURE INTO
REGIME OF UPSLOPE ASCENT...AS WELL AS CONTRIBUTING TO DIRECTIONAL
SHEAR AND STORM-RELATIVE INFLOW.  MEANWHILE 35-45 KT EFFECTIVE SHEAR
MAGNITUDES ARE EXPECTED...INDICATING SOME SUPERCELL POTENTIAL WITH
RISK OF LARGE HAIL AND ISOLATED DAMAGING GUSTS.

..EDWARDS.. 07/26/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GLD...PUB...BOU...CYS...

LAT...LON   38360355 40260466 42330537 42360451 40870269 38430222
            38090267 38360355

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