Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS03 KWNS 220730
SWODY3
SPC AC 220729

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0229 AM CDT FRI AUG 22 2014

VALID 241200Z - 251200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
A FEW STRONG/POSSIBLY SEVERE STORMS WILL BE POSSIBLE DURING THE
AFTERNOON AND EVENING ACROSS PORTIONS OF THE UPPER MISSISSIPPI
VALLEY VICINITY ON SUNDAY.

...SYNOPSIS...
SOME SUPPRESSION OF THE MS VALLEY/GREAT LAKES UPPER RIDGE IS PROGGED
DAY 3...AS AN UPPER LOW/TROUGH IS SHUNTED ENEWD ACROSS THE NRN
PLAINS INTO SRN MANITOBA BY THE END OF THE PERIOD.  MEANWHILE...THE
BROADER TROUGH OVER THE W WILL BE MAINTAINED DESPITE EJECTION OF
THIS FEATURE...AS ADDITIONAL SHORT-WAVE TROUGHING DIGS SWD OUT OF
WRN CANADA INTO THE PAC NW.

AT THE SURFACE...A COLD FRONT IS FORECAST TO ADVANCE EWD ACROSS THE
N CENTRAL U.S. WITH TIME...AS THE SURFACE LOW SHIFTS INTO THE SRN
MANITOBA/WRN ONTARIO VICINITY.  ANY ORGANIZED SEVERE RISK THIS
PERIOD IS FORECAST TO BE ASSOCIATED WITH THIS SURFACE SYSTEM AND
ASSOCIATED/EJECTING UPPER LOW.

...UPPER MS VALLEY VICINITY...
MODEL DIFFERENCES WITH RESPECT TO EVOLUTION/LOCATION OF SYNOPTIC
FEATURES PERSISTS THIS PERIOD -- AGAIN RESULTING IN LOW CONFIDENCE
WITH RESPECT TO DELINEATING LOCATION AND DEGREE OF ANY SEVERE RISK
ASSOCIATED WITH THIS STORM SYSTEM.

SIMILAR TO DAY 2...ONGOING STORMS AT THE START OF THE PERIOD --
ALBEIT FARTHER N -- WILL AGAIN BE LIKELY TO ALTER THE THERMODYNAMIC
ENVIRONMENT.  HOWEVER...WITH A SHARPENING BELT OF SWLY FLOW ALOFT
OVER THE UPPER MS VALLEY AS THE EJECTING LOW IMPINGES ON PERSISTENT
RIDGING...SHEAR SUPPORTIVE OF ORGANIZED STORMS WILL BE PRESENT.
THUS -- DESPITE LACK OF CLARITY ON THE DETAILS...WILL INTRODUCE A 5%
SEVERE PROBABILITY AREA CENTERED OVER THE UPPER MS VALLEY FOR THE
AFTERNOON/EVENING HOURS.

..GOSS.. 08/22/2014




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