Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 161242
SWODY1
SPC AC 161240

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0740 AM CDT TUE SEP 16 2014

VALID 161300Z - 171200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
THE THREAT FOR WIDELY SCATTERED THUNDERSTORMS...POTENTIALLY CAPABLE
OF ISOLATED LARGE HAIL...WILL PROBABLY DEVELOP OVER EASTERN KANSAS
AND WESTERN MISSOURI LATE TONIGHT AND EARLY MORNING WEDNESDAY.
ELSEWHERE...ISOLATED TO SCATTERED GENERAL STORMS WILL BE POSSIBLE
ACROSS MUCH OF THE SOUTHERN INTO THE WESTERN U.S.

...SYNOPSIS...

THE LARGE-SCALE PATTERN WILL REMAIN CHARACTERIZED BY A TROUGH OVER
THE FAR NERN PACIFIC...RIDGING ACROSS THE INTERIOR WEST...AND A
BROAD TROUGH E OF THE ROCKIES. A SERIES OF WEAK PERTURBATIONS WILL
PROGRESS THROUGH THIS AIRFLOW PATTERN...THE MOST NOTABLE OF WHICH
WILL TRACK FROM THE NRN HIGH PLAINS INTO THE MID MS VALLEY.

AT THE SURFACE...CYCLOGENESIS WILL OCCUR LATER TODAY OVER ERN CO
WITH THIS FEATURE DEVELOPING INTO WRN OR CNTRL KS TONIGHT. THIS
PROCESS WILL PROMOTE THE NWD MOVEMENT OF AN INITIALLY STALLED
SURFACE FRONT THROUGH THE WRN HALF OF KS AND THE OZARK PLATEAU
REGION.

...ERN KS/WRN MO LATE TONIGHT...

A MOIST BOUNDARY-LAYER /I.E. DEWPOINTS IN THE 60S/ PRESENT S OF THE
STALLED SURFACE FRONT OVER THE SRN PLAINS WILL BE ADVECTED NWD AS
THE LOW-LEVEL MASS FIELD RESPONDS TO THE LEE CYCLOGENESIS. AT THE
SAME TIME...AN ELONGATING LOBE OF STEEPER MID-LEVEL LAPSE RATES WILL
OVERSPREAD THE CNTRL PLAINS AND OZARK PLATEAU WITHIN A CHANNEL OF
HIGHER-MOMENTUM NWLY MID-LEVEL FLOW ATTENDING THE ABOVE-MENTIONED
IMPULSE. THESE DIFFERENTIAL ADVECTIONS WILL YIELD A CORRIDOR OF
MODERATE INSTABILITY /I.E. MUCAPE OF 1000-1500 J PER JG/ BY TONIGHT
ALONG AND TO THE N OF THE SURFACE FRONT.

DCVA ASSOCIATED WITH THE MIGRATORY SHORT-WAVE TROUGH WILL LARGELY
REMAIN DISPLACED TO THE N OF THE REGION WHICH COUPLED WITH
PERSISTENT CAPPING AT THE BASE OF THE EML CAST UNCERTAINTY ON
NOCTURNAL STORM COVERAGE. HOWEVER...IT DOES APPEAR THAT MODEST
ISENTROPIC ASCENT ATOP THE FRONTAL SURFACE MAY BE SUFFICIENT TO
FOSTER A FEW ELEVATED STORMS LATE TONIGHT INTO EARLY WEDNESDAY. A
LOW-PROBABILITY RISK FOR MARGINALLY SEVERE HAIL WILL EXIST WITH
THESE STORMS.

...ELSEWHERE...

A FEW STRONG STORMS WILL BE POSSIBLE THIS AFTERNOON FROM THE
CAROLINAS TO GULF COAST AS FORCING FOR ASCENT ASSOCIATED WITH A
MID-LEVEL IMPULSE MOVING INTO THE TN VALLEY INTERACTS WITH A MOIST
AND AT LEAST MODESTLY UNSTABLE ENVIRONMENT. GIVEN THE HIGH MOISTURE
CONTENT OF THE AMBIENT AIR MASS AND POTENTIAL FOR STEEP LOW-LEVEL
LAPSE RATES...LOCALLY STRONG WIND GUSTS WILL ACCOMPANY THE MOST
INTENSE STORMS.

..MEAD/DIAL.. 09/16/2014



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