Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 310535
SWODY2
SPC AC 310534

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1234 AM CDT TUE MAY 31 2016

VALID 011200Z - 021200Z

...THERE IS A MRGL RISK OF SVR TSTMS CENTERED OVER THE UPPER GREAT
LAKES REGION AND THE NRN HALF OF IL...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF CENTRAL AND SRN
TX...

...SUMMARY...
A FEW STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THE UPPER
GREAT LAKES AND SOUTHWESTWARD TO NORTHEAST MISSOURI/WEST-CENTRAL
ILLINOIS MAINLY WEDNESDAY AFTERNOON AND EARLY EVENING.  A FEW SEVERE
THUNDERSTORMS MAY ALSO DEVELOP ACROSS PORTIONS OF SOUTHERN TEXAS
DURING THE LATE AFTERNOON/EARLY EVENING.

...SYNOPSIS...
THE MAIN BELT OF WLY FLOW ALOFT WILL REMAIN ACROSS SRN CANADA AND
THE ADJACENT NWRN/N CENTRAL U.S. WEDNESDAY/DAY 2...WITH AN EMBEDDED
TROUGH TO SHIFT ACROSS THE UPPER MS VALLEY AND INTO THE UPPER GREAT
LAKES WITH TIME.  MEANWHILE...A WEAKER TROUGH/LOW IS FORECAST TO
CROSS NRN MEXICO AND TX THROUGH THE PERIOD.

AT THE SURFACE...A VERY WEAK COOL FRONT IS FORECAST TO MOVE EWD
ACROSS THE MID AND LOWER MS VALLEY AND SWD ACROSS TX DURING THE
PERIOD...AS A WEAK/PARENT LOW DRIFTS ACROSS THE MIDWEST.  A SECOND
FRONT -- TRAILING SWD FROM A STRONGER NRN MN/WRN ONTARIO LOW -- WILL
MOVE ACROSS THE UPPER MS VALLEY AND INTO THE UPPER GREAT LAKES
REGION TROUGH THE PERIOD.  THESE TWO BOUNDARIES WILL FOCUS
CONVECTION -- AND LOW-END SEVERE RISK -- DURING THE AFTERNOON AND
EARLY EVENING HOURS.

...UPPER GREAT LAKES SWWD TO ERN IA/NERN MO/NRN AND WRN IL...
WEAK DESTABILIZATION IS FORECAST ACROSS THE UPPER GREAT LAKES REGION
AND SWD INTO THE MIDWEST...AHEAD OF THE COLD FRONT SHIFTING EWD
ACROSS THE REGION.  THOUGH A SEASONABLY MOIST WARM SECTOR IS
EXPECTED...CLOUDS/ONGOING PRECIPITATION ALONG AND AHEAD OF THE
BOUNDARY SHOULD LIMIT OVERALL CAPE DEVELOPMENT.

STILL...EXPECT AN AFTERNOON/DIURNAL UPTICK IN CONVECTIVE INTENSITY
TO OCCUR THROUGH LATE AFTERNOON...WITH STORM ORGANIZATION/LONGEVITY
ENHANCED LOCALLY BY MODERATE /40 TO 45 KT/ SWLY FLOW OVER THE UPPER
MS VALLEY/UPPER GREAT LAKES AHEAD OF THE ADVANCING MID-LEVEL TROUGH.
ALONG WITH SOME RISK FOR MARGINAL HAIL...A FEW OF THE STRONGER CELLS
MAY PROVE CAPABLE OF PRODUCING GUSTY/LOCALLY DAMAGING WINDS INTO THE
EARLY EVENING HOURS.

...MUCH OF THE RIO GRANDE VALLEY AND INTO THE HILL COUNTRY OF TX...
AS A SURFACE COOL FRONT SAGS SWD ACROSS TX AND BECOMES W-E ORIENTED
ACROSS THE RIO GRANDE VALLEY/S TX VICINITY DURING THE
AFTERNOON...LARGE-SCALE ASCENT AHEAD OF THE APPROACHING UPPER TROUGH
-- FOCUSED INVOF THE SURFACE BOUNDARY -- SHOULD SUPPORT INITIATION
OF AFTERNOON SHOWERS AND SCATTERED THUNDERSTORMS AS 1000 TO 2000
J/KG MIXED-LAYER CAPE DEVELOPS INVOF THE FRONT.  THOUGH ONLY MODEST
/20 TO 25 KT/ MID-LEVEL WLYS ARE EXPECTED ACROSS THE
AREA...LOW-LEVEL ESELY WINDS NEAR AND TO THE COOL SIDE OF THE FRONT
WILL CONTRIBUTE TO DEEP-LAYER SHEAR SUFFICIENT FOR ORGANIZED
UPDRAFTS/SOME MID-LEVEL ROTATION WITH A FEW STRONGER CELLS.  AS
SUCH...LOW-PROBABILITY RISK FOR HAIL/WIND REMAINS
APPARENT...PRIMARILY DURING THE AFTERNOON AND EARLY EVENING HOURS.

..GOSS.. 05/31/2016

$$



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