Severe Storm Outlook Narrative (AC)
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000
ACUS48 KWNS 010900
SWOD48
SPC AC 010859

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0359 AM CDT WED APR 01 2015

VALID 041200Z - 091200Z

...DISCUSSION...
MEDIUM RANGE GUIDANCE DEPICTS THE ADVANCING ERN U.S. COLD FRONT
MOVING OFF THE ATLANTIC AND GULF COASTS EARLY DAY 4 /SAT. 4-4/...AND
FULLY CLEARING THE FL PENINSULA OVERNIGHT.  IN ITS WAKE...A
LARGE/SUBSTANTIAL AIRMASS OF POLAR ORIGIN WILL SPREAD ACROSS THE
SERN U.S. AND GULF OF MEXICO.  WITH THE HIGH SLIDING EWD DAY
5...SOME RETURN OF INCOMPLETELY MODIFIED GULF AIR INTO THE CENTRAL
U.S. WILL COMMENCE -- AS WSWLYS ALOFT SUPPORT LEE SURFACE
CYCLOGENESIS AND ASSOCIATED EVOLUTION OF LOW-LEVEL SLYS ACROSS THE
PLAINS.

WHILE QUALITY OF MOISTURE RETURN WILL CONTINUE TO IMPROVE WITH
TIME...MEAN RIDGING PREVAILING OVER THE CENTRAL U.S. DOWNSTREAM OF
AN EVOLVING WRN U.S. TROUGH SUGGESTS THAT ANY SEVERE RISK THROUGH
ROUGHLY DAY 6 SHOULD REMAIN LIMITED -- AND DRIVEN BY SMALL-SCALE
DISTURBANCES ALOFT EJECTING INTO THE MEAN RIDGE.

EVENTUALLY...MORE SUBSTANTIAL HEIGHT FALLS INTO THE CENTRAL U.S.
WILL RESULT IN INCREASING POTENTIAL FOR MORE ORGANIZED/WIDESPREAD
SEVERE RISK...THOUGH MODEL DIFFERENCES BECOME PRONOUNCED DAYS 7-8
SUCH THAT LOW CONFIDENCE PREVAILS WITH RESPECT TO NARROWING SPECIFIC
AREAS AND TIMES FOR CONCENTRATED RISK FOR SEVERE STORMS.
THEREFORE...WHILE RISK AREAS WILL LIKELY BE REQUIRED IN
SHORTER-RANGE OUTLOOKS INTO EARLY NEXT WEEK...PREDICTABILITY REMAINS
SUFFICIENTLY LOW SO AS TO PRECLUDE DELINEATION OF ANY SEVERE WEATHER
AREAS ATTM.

..GOSS.. 04/01/2015



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