Severe Storm Outlook Narrative (AC)
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
ACUS01 KWNS 021251
SWODY1
SPC AC 021249

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0749 AM CDT THU OCT 02 2014

VALID 021300Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL AND E TX NNE INTO
THE OZARKS...MID-MS AND LWR OH VLYS...

...SUMMARY...
WIDESPREAD THUNDERSTORMS ARE EXPECTED TODAY THROUGH EARLY FRIDAY
ALONG AND AHEAD OF A COLD FRONT MOVING EAST ACROSS THE SOUTHERN AND
CENTRAL PLAINS INTO THE MID-MISSISSIPPI AND TENNESSEE VALLEYS. THE
STORMS SHOULD ORGANIZE INTO LINES AND LIKELY WILL PRODUCE STRONG TO
DAMAGING WIND GUSTS...HAIL...AND PERHAPS A COUPLE TORNADOES. THE
GREATEST SEVERE THREAT WILL EXTEND FROM NORTHEAST TEXAS AND EASTERN
OKLAHOMA INTO ARKANSAS AND THE OZARKS.

...SYNOPTIC SETUP...
PATTERN WILL BECOME MORE AMPLIFIED ACROSS THE CONUS THIS PERIOD AS
POTENT SRN RCKYS SHORTWAVE TROUGH EJECTS E...AND LATER NE...ACROSS
THE SRN PLNS AND LWR MS VLY AHEAD OF UPSTREAM JET STREAK NOW MOVING
SE ACROSS ALBERTA. THE RCKYS IMPULSE SHOULD REACH CNTRL OK THIS EVE
AND SRN IL BY 12Z FRI AS A LARGER-SCALE TROUGH EVOLVES OVER THE
PLNS/MS VLY.

AT THE SFC...ELONGATED LOW OVER THE CNTRL/SRN PLNS SHOULD TRACK
SLOWLY E INTO MO AND WRN AR THIS EVE BEFORE DEEPENING AND
ACCELERATING NNE TO LK MI EARLY FRI. COLD FRONT TRAILING SW FROM THE
LOW WILL BE THE MAIN FOCUS FOR TSTM DEVELOPMENT THROUGH THE
PERIOD...WITH ADDITIONAL STORMS LIKELY TO PERSIST IN PRE-FRONTAL WAA
ZONE EXTENDING ENE INTO THE MID-MS/LWR OH VLYS.

...SRN PLNS/LWR MS VLY INTO MID MS/LWR OH VLYS TODAY THROUGH EARLY
FRI...

VERY MOIST AIR /PW AROUND 1.75/ NOW OVER ERN PORTIONS OF THE SRN
PLNS AND LWR MS VLY WILL SPREAD FARTHER NNE INTO THE
MID-MS...TN...AND OH VLYS LATER TODAY AND TNGT AS DEEP SSW TO SWLY
FLOW BACKS AND STRENGTHENS AND OF SRN RCKYS UPR IMPULSE.

TSTMS NOW OVER ERN OK AND WRN/CNTRL MO ARE FORMING WITHIN
PRE-FRONTAL WARM CONVEYOR BELT. THIS ACTIVITY SHOULD PERSIST THROUGH
LATER THIS MORNING AND MAY POSE A SPORADIC RISK OF LOCALLY DMGG
WIND/HAIL GIVEN ACCESS TO RELATIVELY STEEP MID-LVL LAPSE RATES AND
40+ KT SWLY DEEP SHEAR. FARTHER W...STORMS IN CNTRL KS/FAR S CNTRL
NEB ARE ASSOCIATED WITH LEADING EDGE OF A BAND OF ASCENT LOOSELY
TIED TO THE RCKYS UPR TROUGH. THESE STORMS COULD POSE A SVR HAIL
RISK EWD INTO NE KS AND PERHAPS NW MO /REF MCD 1793/...BEFORE THE
ASCENT BAND MOVES FARTHER E BEYOND NARROW...ELEVATED EML PLUME NOW
SUPPORTING THE CONVECTION.

TOWARD MIDDAY AND THROUGH THE AFTN...ADDITIONAL TSTMS ARE EXPECTED
TO FORM WITH SFC HEATING ALONG AND AHEAD OF ACCELERATING CNTRL/SRN
PLNS COLD FRONT. COMBINATION OF STEEP MID-LVL LAPSE RATES AND RICH
LOW-LVL MOISTURE WITH 40-50 KT...UNIDIRECTIONAL...SWLY 700-500 MB
FLOW AND INCREASING FORCING FOR ASCENT SUGGESTS THAT INITIAL
SUSTAINED STORMS/SUPERCELLS SHOULD FAIRLY QUICKLY MERGE INTO AN
EXTENSIVE BROKEN SQLN FROM THE MO OZARKS SWWD INTO CNTRL TX. WHILE A
COUPLE TORNADOES CANNOT BE RULED OUT...AND LARGE HAIL COULD OCCUR IN
ERN OK AND TX...THE MAIN SVR THREAT SHOULD BECOME DMGG WIND AS SETUP
WILL BE FAVORABLE FOR EMBEDDED LEWPS/BOWS. THIS ACTIVITY SHOULD
CONTINUE E/SE INTO THE LWR MS AND TN VLYS TNGT THROUGH EARLY
FRI...WITH A CONTINUING RISK FOR DMGG WIND AND PERHAPS A BRIEF
TORNADO OR TWO.

..CORFIDI/COHEN.. 10/02/2014



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.