Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 110552
SWODY1
SPC AC 110550

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1250 AM CDT FRI JUL 11 2014

VALID 111200Z - 121200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL HIGH PLAINS TO
MID-MO VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF N MN...

...SUMMARY...
ISOLATED SEVERE STORMS ARE POSSIBLE THIS AFTERNOON AND EVENING FROM
PARTS OF THE UPPER MISSISSIPPI VALLEY TO CENTRAL HIGH PLAINS.

...SYNOPSIS...
A QUASI-ZONAL FLOW REGIME WITH MODERATE MID-LEVEL WLYS WILL PREVAIL
OVER THE N-CNTRL STATES AS AN UPPER-LEVEL TROUGH BECOMES CENTERED
ACROSS NRN MANITOBA. TRAILING PORTION OF A COLD FRONT ASSOCIATED
WITH THIS TROUGH SHOULD EXTEND ACROSS THE UPPER MS VALLEY TO NRN
PLAINS THIS AFTERNOON. FARTHER S...A LEE TROUGH WILL REMAIN ANCHORED
OVER THE CNTRL HIGH PLAINS WITH A QUASI-STATIONARY FRONT ARCING
ACROSS S NEB AND A DRYLINE EXTENDING S THROUGH CNTRL KS. A WEAK
MID-LEVEL IMPULSE OFF THE NRN CA/ORE COAST WILL SHIFT SLOWLY N.

...CNTRL HIGH PLAINS TO MID-MO VALLEY...
RESERVOIR OF RICHER LOW-LEVEL MOISTURE /CHARACTERIZED BY 60S SURFACE
DEWPOINTS/ WILL EXIST BENEATH STEEP LAPSE RATES N OF THE
QUASI-STATIONARY FRONT. ROBUST DIABATIC WARMING S OF THE FRONT
/SURFACE TEMPERATURES APPROACHING 100 DEG F/ WILL CONTRIBUTE TO
MLCAPE REACHING 1500-2500 J/KG. THE REGION WILL RESIDE ON THE SRN
PERIPHERY OF MODEST MID-LEVEL WLYS...BUT WITH AN ELY COMPONENT TO
LOW-LEVEL FLOW...EFFECTIVE SHEAR SHOULD REACH 25-35 KT. AFTERNOON
STORMS WILL LIKELY INITIATE ALONG THE HIGHER TERRAIN AND DEVELOP EWD
IN THE EVENING AS THE LLJ STRENGTHENS OVER THE CNTRL PLAINS.
MULTICELL CLUSTERS SHOULD BE THE PREDOMINANT MODE WITH SEVERE
HAIL/WIND AS THE PRIMARY HAZARDS. INCREASINGLY SUBSTANTIAL MLCIN FRI
NIGHT RENDERS UNCERTAINTY IN THE ERN EXTENT OF ORGANIZED SEVERE RISK
TOWARDS IA.

...N MN...
MIDDLE TO UPPER 60S SURFACE DEW POINTS SHOULD LIE AHEAD OF THE
IMPINGING COLD FRONT...WHERE ROBUST DESTABILIZATION IS ANTICIPATED
IN THE WAKE OF SCATTERED MORNING CONVECTION. MLCAPE SHOULD REACH
1500-2500 J/KG BY PEAK HEATING. MID/UPPER-LEVEL SPEED SHEAR SHOULD
BE STRONG BETWEEN 700-250 MB...SUPPORTING POTENTIAL FOR ORGANIZED
UPDRAFTS. UNCERTAINTY REMAINS IN THE DEGREE OF STORM COVERAGE GIVEN
LITTLE MID-LEVEL HEIGHT CHANGE AND GENERALLY VEERED LOW-LEVEL WINDS
AHEAD OF THE BOUNDARY. AMIDST MINIMAL MLCIN...SUFFICIENT SURFACE
CONVERGENCE MAY EXIST FOR ISOLATED STORMS PRIMARILY PRODUCING SEVERE
HAIL/WIND.

...SW ORE/NE CA...
GUIDANCE IS CONSISTENT IN DEPICTING A BELT OF ENHANCED MID-LEVEL
SLYS ACROSS THE NRN SIERRA NV TO SRN CASCADE MTNS THIS AFTERNOON.
ALTHOUGH HODOGRAPHS SHOULD REMAIN RELATIVELY SMALL...EFFECTIVE SHEAR
OF 25-30 KT ALONG WITH STEEP TROPOSPHERIC LAPSE RATES COULD SUPPORT
A COUPLE OF MARGINALLY SEVERE WIND/HAIL EVENTS.

..GRAMS/MOSIER.. 07/11/2014



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