Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS02 KWNS 301729
SWODY2
SPC AC 301728

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT MON MAY 30 2016

VALID 311200Z - 011200Z

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE SRN AND CNTRL PLAINS
NNEWD INTO THE LOWER MO VALLEY AND UPPER MS VALLEY...

...THERE IS A MRGL RISK OF SVR TSTMS ALONG THE CNTRL AND ERN GULF
COAST INTO NRN FL...

...SUMMARY...
ISOLATED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TUESDAY
AFTERNOON AND EARLY EVENING FROM THE UPPER MISSISSIPPI VALLEY
SOUTHWESTWARD INTO THE SOUTHERN GREAT PLAINS.  LOCALIZED STRONG
THUNDERSTORMS ARE POSSIBLE ALONG THE CENTRAL AND EASTERN GULF COAST
INTO NORTHERN FLORIDA TUESDAY AFTERNOON.

...SRN AND CNTRL PLAINS...
AN UPPER-LEVEL TROUGH WILL MOVE INTO THE SRN AND CNTRL PLAINS ON
TUESDAY. AT THE SFC...A COLD FRONT WILL MOVE SEWD ACROSS THE CNTRL
HIGH PLAINS WITH A MOIST AND UNSTABLE AIRMASS LOCATED AHEAD OF THE
FRONT IN THE SRN AND CNTRL PLAINS. SFC DEWPOINTS IN THE MID TO UPPER
60S F ALONG WITH MODERATE INSTABILITY SHOULD CHARACTERIZE AN
UNCAPPED WARM SECTOR BY TUESDAY AFTERNOON. DUE TO SFC
HEATING...SCATTERED THUNDERSTORMS APPEAR LIKELY TO DEVELOP ACROSS
PARTS OF THE WARM SECTOR IN THE SRN AND CNTRL PLAINS BY AFTERNOON.
THE MOST FAVORED AREA FOR THUNDERSTORM DEVELOPMENT WOULD BE FROM
WCNTRL TX EXTENDING NWD INTO WRN OK AND SCNTRL KS WHERE THE
GFS...NAM AND ECMWF SHOW SEVERAL AREAS OF CONVECTIVE PRECIPITATION
BY EARLY TO MID AFTERNOON. FORECAST SOUNDINGS AT 21Z/TUE ALONG THIS
CORRIDOR FROM SAN ANGELO NWD TO WICHITA FALLS AND GAGE SHOW THE
STRONGEST INSTABILITY IN WCNTRL TX WITH MLCAPE UP TO 3000 J/KG AND
SHOW LESS INSTABILITY IN WRN OK WITH MLCAPE OF 1000 TO 1500 J/KG.
WIND PROFILES HAVE SOME DIRECTIONAL SHEAR BUT NOT MUCH SPEED SHEAR
IN THE MID-LEVELS SUGGESTING THAT CELLS WILL HAVE TROUBLE ORGANIZING
TUESDAY AFTERNOON. IN SPITE OF THIS...MULTICELLS THAT DEVELOP NEAR
MAXIMA IN INSTABILITY MAY BE ABLE TO PRODUCE HAIL AND STRONG WIND
GUSTS.

...LOWER MO VALLEY/UPPER MS VALLEY...
AN UPPER-LEVEL LOW WILL MOVE EWD ACROSS THE NRN PLAINS WITH AN
ASSOCIATED UPPER-LEVEL TROUGH EXTENDING SWD INTO THE CNTRL PLAINS ON
TUESDAY. AT THE SFC...A COLD FRONT WILL ADVANCE SEWD INTO WRN MN AND
THE MID MO VALLEY EXTENDING SWWD INTO THE CNTRL PLAINS. AHEAD OF THE
FRONT...SFC DEWPOINTS SHOULD BE IN THE LOWER TO MID 60S F. AS
INSTABILITY DEVELOPS AND LOW-LEVEL CONVERGENCE INCREASES ALONG AND
AHEAD OF THE FRONT...SCATTERED THUNDERSTORM DEVELOPMENT SHOULD TAKE
PLACE DURING THE AFTERNOON. MODEL FORECASTS SUGGEST THAT CELLS COULD
DEVELOP INTO A LINE ALONG THE FRONT WITH THE LINE MOVING ESEWD INTO
THE UPPER MS VALLEY DURING THE MID TO LATE AFTERNOON. FORECAST
SOUNDINGS ALONG THIS CORRIDOR AT 21Z SHOW MLCAPE IN THE 1000 TO 1500
J/KG RANGE AND HAVE SOME DIRECTIONAL SHEAR IN THE LOW TO MID-LEVELS.
IN ADDITION...LOW-LEVEL FLOW IS FORECAST TO INCREASE DURING THE LATE
AFTERNOON WHICH ALONG WITH STEEPENING LOW-LEVEL LAPSE RATES COULD BE
ENOUGH FOR A MARGINAL WIND DAMAGE THREAT. HAIL COULD ALSO OCCUR WITH
THE STRONGER CELLS EMBEDDED THE LINE.

...CNTRL AND ERN GULF COAST...
ALTHOUGH MID-LEVEL FLOW IS EXPECTED TO BE RELATIVELY WEAK ALONG THE
CNTRL AND ERN GULF COAST...A VERY MOIST AIRMASS WILL BE IN PLACE ON
TUESDAY. SFC DEWPOINTS IN THE LOWER 70S F WILL CONTRIBUTE TO
MODERATE INSTABILITY BY MIDDAY FROM SRN MS EWD TO NRN FL. AS
LOW-LEVEL CONVERGENCE INCREASES ALONG SEA-BREEZE
BOUNDARIES...THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE EARLY
AFTERNOON. THE MOIST BOUNDARY LAYER COMBINED WITH STEEP LOW-LEVEL
LAPSE RATES MAY RESULT IN A FEW STRONG WIND GUSTS.

..BROYLES.. 05/30/2016

$$


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