Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 181738
SWODY2
SPC AC 181737

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1237 PM CDT SAT APR 18 2015

VALID 191200Z - 201200Z

...THERE IS AN ENH RISK OF SVR TSTMS CENTERED OVER ARKANSAS AND THE
ARKLATEX AND SURROUNDING AREAS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN KS/ERN OK/E TX EWD TO
THE SRN ATLANTIC COAST...

...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE SLIGHT RISK
AREA AND INCLUDING PARTS OF THE OH VALLEY...DEEP S TX...AND NRN
FL...

...SUMMARY...
THUNDERSTORMS -- SOME CAPABLE OF PRODUCING LARGE HAIL AND LOCALLY
DAMAGING WINDS -- WILL BE POSSIBLE FROM EASTERN PORTIONS OF THE
CENTRAL AND SOUTHERN PLAINS EASTWARD ACROSS THE MID SOUTH AND
SOUTHEAST ON SUNDAY.

...SYNOPSIS...
COMPLEX EVOLUTION OF THE UPPER FLOW FIELD ACROSS THE U.S. IS PROGGED
SUN...AS MULTIPLE SHORTER-WAVELENGTH LOWS/TROUGHS BETWEEN THE
ROCKIES AND THE APPALACHIANS GRADUALLY EVOLVE INTO A MORE
CONSOLIDATED/EXPANSIVE TROUGH ACROSS THIS AREA BY THE END OF THE
PERIOD.  MEANWHILE...RIDGING WILL PREVAIL OVER BOTH THE W AND E
COASTS.

AT THE SURFACE...EVOLUTION OF THE PATTERN WILL BE SIMILARLY
COMPLEX...AS A COLD FRONT SWEEPS SEWD ACROSS THE PLAINS WITH TIME
WHILE A WARM FRONT SHIFTS NEWD ACROSS THE ERN STATES.  A WEAKER LOW
AND ITS PARENT UPPER FEATURE SHIFTING OUT OF ERN OK INTO THE OZARKS
VICINITY WILL ALSO PLAY A ROLE IN THE CONVECTIVE FORECAST THIS
PERIOD.

...SERN KS/ERN OK/E TX INTO THE LOWER MS VALLEY...
CONVECTION IS PROGGED TO INCREASE ACROSS SERN KS/ERN OK/THE ARKLATEX
REGION DURING THE AFTERNOON...AS HEATING/DESTABILIZATION INCREASE
THROUGH THE DAY AHEAD OF AN ESEWD-MOVING VORT MAX PROGGED TO BE
CROSSING THIS AREA.  WITH ENHANCED FLOW FIELD ALOFT ASSOCIATED WITH
THIS FEATURE SPREADING ACROSS THE OZARKS/ARKLATEX VICINITY DURING
THE AFTERNOON...DEVELOPING STORMS SHOULD ORGANIZE/BECOME
SEVERE...WITH HAIL AND DAMAGING WINDS THE PRIMARY THREATS.  GREATEST
INSTABILITY IS FORECAST FROM ROUGHLY CENTRAL AR SWWD INTO E
TX...WHERE MIXED-LAYER CAPE IN EXCESS OF 3000 J/KG WILL BE POSSIBLE.
 THOUGH CAPPING SHOULD LIMIT STORM COVERAGE WITH SWWD EXTENT INTO
TX...THE ENVIRONMENT WILL BE SUPPORTIVE OF LARGE SUPERCELLS CAPABLE
OF PRODUCING VERY LARGE HAIL ACROSS THIS AREA.  WITH TIME...STORMS
SHOULD SPREAD ACROSS AR/SRN MO/LA...REACHING THE LOWER MS VALLEY
THROUGH THE EVENING...WITH SOME SEVERE RISK LIKELY TO LINGER INTO
THE OVERNIGHT HOURS.

...THE MID SOUTH AND SOUTHEAST STATES...
WIDESPREAD ONGOING CONVECTION IS FORECAST ACROSS PARTS OF KY/TN AND
INTO GA AND THE CAROLINAS...WHICH SHOULD SPREAD ENEWD WITH TIME.
THOUGH THIS CONVECTION/CLOUD COVER SHOULD LIMIT DESTABILIZATION
POTENTIAL IN THESE AREAS...AFTERNOON STORM INTENSIFICATION APPEARS
POSSIBLE FROM PARTS OF SRN KY/TN AND INTO GA...WHERE AT LEAST SOME
HEATING/DESTABILIZATION IS EXPECTED.  THOUGH SOMEWHAT
UNIDIRECTIONAL...THE FLOW FIELD ACROSS THIS AREA WILL BE STRONG
ENOUGH TO SUPPORT ORGANIZED STORMS/STORM CLUSTERS -- ALONG WITH
ATTENDANT RISK FOR HAIL AND DAMAGING WINDS.  STORMS ARE EXPECTED TO
SPREAD NEWD WITH TIME ACROSS GA AND INTO SC AND POSSIBLY PARTS OF NC
THROUGH THE EVENING...WITH SEVERE RISK LIKELY TO PERSIST THROUGH
SUNSET.  WHILE A HIGHER-PROBABILITY RISK AREA MAY BE REQUIRED IN
LATER OUTLOOKS ACROSS PARTS OF THIS AREA...QUESTIONS REGARDING
DEGREE OF DESTABILIZATION DUE TO PRIOR/ONGOING CONVECTION PRECLUDE
ADDITION OF ENHANCED RISK ATTM.

..GOSS.. 04/18/2015




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