Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 051258
SWODY1
SPC AC 051256

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0756 AM CDT SUN JUL 05 2015

VALID 051300Z - 061200Z

...THERE IS AN ENH RISK OF SVR TSTMS OVER PARTS SD AND MN...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN PLNS AND
UPR MS VLY...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE LWR MS
VLY/CNTRL GULF CST...

...THERE IS A MRGL RISK OF SVR TSTMS FROM THE CNTRL HIGH PLNS NE
INTO THE UPR MS VLY...

...THERE IS A MRGL RISK OF SVR TSTMS OVER PARTS OF THE SOUTH AND
SERN STATES...

...SUMMARY...
THUNDERSTORMS WITH LARGE HAIL...DAMAGING WIND...AND POSSIBLY A
TORNADO OR TWO WILL OCCUR LATER TODAY INTO TONIGHT OVER PARTS OF THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY...ESPECIALLY OVER SOUTH
DAKOTA...NORTHERN NEBRASKA...SOUTHWEST MINNESOTA...AND NORTHWEST
IOWA.

...SYNOPTIC SETUP...
THE MAIN BELT OF THE WLYS WILL CONTINUE ACROSS SRN CANADA INTO NEW
ENGLAND. A FAIRLY STRONG/POSITIVE-TILT SHORTWAVE TROUGH IN THIS
FLOW...NOW OVER AB...WILL REACH WRN ONT EARLY MON. FARTHER
S...WEAKER SRN STREAM JET WILL PERSIST FROM THE CNTRL/SRN PLNS
ACROSS THE CNTRL GULF CST INTO THE CAROLINAS...ALONG SRN PERIPHERY
OF SLOWLY-PROGRESSIVE TN VLY UPR TROUGH.

COLD FRONT ASSOCIATED WITH NRN STREAM IMPULSE WILL PROGRESS STEADILY
S ACROSS THE NRN HIGH PLNS AND SE ACROSS THE NRN PLNS/UPR MS VLY
TODAY/TNGT...PRECEDED BY A LEE TROUGH OVER THE DAKOTAS/NEB.

...NRN PLNS/UPR MS VLY LATER TODAY THROUGH EARLY MON...
SCTD CLUSTERS OF STRONG TO OCCASIONALLY SVR STORMS MAY AFFECT PARTS
OF THE DAKOTAS ALONG AND N OF COLD FRONT AND PRE-FRONTAL TROUGH
THROUGH EARLY AFTN...AS WEAK WAA/MOISTURE TRANSPORT CONTINUE ON SERN
FRINGE OF AB UPR TROUGH.

MORE ROBUST AND WIDESPREAD STRONG TO SVR TSTM DEVELOPMENT
SHOULD...HOWEVER... OCCUR NEAR THE COLD FRONT AND SFC TROUGH LATER
THIS AFTN FROM SW THROUGH CNTRL AND NE SD AS SFC HEATING AND
DCVA/HEIGHT FALLS ON SRN FRINGE OF THE UPR SYSTEM FURTHER
DESTABILIZE REGION. VERY STEEP MID-LVL LAPSE RATES ATOP SFC
DEWPOINTS IN THE MID-UPR 60S F WILL YIELD SUBSTANTIAL BUOYANCY
AMIDST 40+ KT SW TO WSWLY DEEP SHEAR. INITIAL STORMS IN THIS
ENVIRONMENT COULD INCLUDE A FEW SUPERCELLS CAPABLE OF VERY LARGE
HAIL AND POSSIBLY A COUPLE TORNADOES THROUGH EARLY EVE.

A BIT LATER TNGT...STORM MERGERS/SPREADING COLD POOLS AND NOCTURNAL
STRENGTHENING OF SSWLY LLJ SHOULD FOSTER UPSCALE DEVELOPMENT OF THE
STORMS INTO AN E/SE-MOVING BROKEN SQLN OVER EASTERN SD INTO SRN
MN/NRN IA. THE ASSOCIATED DMGG WIND THREAT WITH THIS ACTIVITY COULD
INCREASE AND PERSIST THROUGH EARLY MON.

...ARKLATEX/LWR MS VLY/SOUTHEAST THIS AFTN...
AFTN HEATING OF MOIST AIR ON SW AND SE FLANKS OF TN VLY/SRN
APPALACHIANS UPR TROUGH SHOULD LEAD TO ANOTHER ROUND OF DIURNALLY
ENHANCED STORMS FROM THE ARKLATEX...E/SE ACROSS THE CNTRL GULF CST
REGION INTO GA/FL...THE ERN CAROLINAS...AND TIDEWATER VA. ASSOCIATED
BAND OF STRONGER LOW TO MID-TROPOSPHERIC FLOW WILL BE SOMEWHAT
RELAXED COMPARED TO THE PAST TWO DAYS. NEVERTHELESS...COMBINATION OF
1.75 INCH PW WITH 25-30 KT 700-500 MB UNIDIRECTIONAL SW FLOW COULD
YIELD BROKEN LINES/SMALL CLUSTERS OF STORMS CAPABLE OF LOCALLY DMGG
WIND FROM AL/GA NE INTO THE CAROLINAS/SE VA. FARTHER W...GREATER
DIRECTIONAL SHEAR AND STEEPER MID-LVL LAPSE RATES WILL EXIST ACROSS
E TX...SRN AR...AND LA/MS...WHERE A FEW TRANSIENT SUPERCELLS WITH
SVR WIND/MARGINALLY SVR HAIL AND PERHAPS A TORNADO MAY OCCUR.

..CORFIDI/LEITMAN.. 07/05/2015



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