Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS03 KWNS 210728
SWODY3
SPC AC 210728

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0228 AM CDT THU AUG 21 2014

VALID 231200Z - 241200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
SCATTERED THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF THE MIDDLE
MISSOURI AND UPPER MISSISSIPPI VALLEYS ON SATURDAY. WHILE THERE IS
STILL A GREAT DEAL OF FORECAST UNCERTAINTY...THE STRONGEST STORMS
MAY PRODUCE SOME HAIL AND GUSTY WINDS.

...SYNOPSIS...

AN UPPER SHORTWAVE TROUGH WILL MOVE OVER THE CNTRL AND NRN PLAINS
AHEAD OF THE MAIN UPPER TROUGH OVER THE WESTERN STATES ON SATURDAY.
FURTHER EAST...THE AMPLIFIED UPPER RIDGE WILL PERSIST OVER THE
CENTRAL U.S. AT THE SFC...LOW PRESSURE OVER THE CENTRAL PLAINS WILL
TRACK NE TOWARD THE ERN DAKOTAS. A TRAILING COLD FRONT WILL SWEEP
ACROSS PARTS OF THE NRN AND CNTRL PLAINS.

...PORTIONS OF THE MID-MO AND UPPER MS VALLEYS...

ANOTHER MESSY SCENARIO IS EXPECTED ON SATURDAY AS THUNDERSTORMS WILL
LIKELY BE ONGOING DURING THE MORNING IN A WARM ADVECTION REGIME
AHEAD OF THE COLD FRONT MOVING ACROSS THE WRN DAKOTAS. FORECAST
SOUNDINGS INDICATE MODEST LAPSE RATES AROUND 6 TO 7 DEG C PER KM
THROUGH A DEEP SATURATED LAYER...LIKELY IMPACTED BY AT LEAST
WIDESPREAD BROKEN CLOUDINESS. WHILE DEWPOINTS WILL BE IN THE
70S...AIDING IN 1500-2500 J/KG MUCAPE VALUES...THIS MAY NOT BE
ENOUGH AS STRONGER FORCING AND MORE FAVORABLE DEEP LAYER SHEAR WILL
NOT BE WELL ALIGNED WITH THE BETTER THERMODYNAMIC ENVIRONMENT.
ADDITIONALLY...DETERMINISTIC GUIDANCE INDICATES QUITE A FEW
DIFFERENCES WITH REGARD TO THE STRENGTH AND TRACK OF THE SFC LOW AND
ALSO THE TIMING OF THE COLD FRONT. SOME HAIL AND GUSTY WINDS MAY BE
POSSIBLE WITH STRONGER STORMS...BUT GIVEN CONSIDERABLE
UNCERTAINTY...ONLY LOW PROBABILITIES WILL BE INTRODUCED AT THIS
TIME.

..LEITMAN.. 08/21/2014




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