DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 151945
SWODY1
SPC AC 151943

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0243 PM CDT SAT MAR 15 2014

VALID 152000Z - 161200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF CENTRAL AND NRN
TX/SRN OK ESEWD INTO THE LOWER MS VALLEY...

...PORTIONS OF SRN OK/TX EWD ACROSS THE LOWER MS VALLEY...
FEW CHANGES ARE BEING MADE TO THE OUTLOOK THIS UPDATE...AS PRIOR
REASONING REMAINS ON TRACK. STORMS HAVE INCREASED AND BECOME
SOMEWHAT BETTER ORGANIZED ACROSS THE N CENTRAL TX VICINITY...WITH
SOME ADDITIONAL UPTICK IN ORGANIZATION/INTENSITY OF THE STORMS
EXPECTED OVER THE NEXT FEW HOURS -- IN AND NEAR WW #29.

LATER...A CONVECTIVE INCREASE IS EXPECTED ACROSS THE LA/SRN MS
VICINITY AS STORMS SPREAD EWD/NEWD OUT OF ERN TX AND THE NWRN GULF.
RISK FOR ISOLATED DAMAGING GUSTS AND A TORNADO OR TWO WILL ACCOMPANY
THESE STORMS THROUGH THE END OF THE PERIOD.

..GOSS.. 03/15/2014

.PREV DISCUSSION... /ISSUED 1129 AM CDT SAT MAR 15 2014/

...SYNOPSIS...
SPLIT FLOW WILL CONTINUE OVER THE CNTRL AND ERN U.S...DOWNSTREAM
FROM AMPLIFIED...SLOWLY PROGRESSIVE RIDGE NOW ALONG THE W CST. LEAD
SRN BRANCH IMPULSE NOW ENTERING W TX SHOULD CONTINUE E INTO CNTRL TX
TODAY AND THEN TURN NE ACROSS THE ARKLATEX TNGT IN RESPONSE TO
UPSTREAM DISTURBANCES NOW MOVING S ACROSS THE FOUR CORNERS/CNTRL
RCKYS. AT THE SAME TIME...SEVERAL LOW-AMPLITUDE FEATURES NOW OVER
NRN MEXICO WILL LIKELY TRACK MORE OR LESS IN TANDEM WITH THE W TX
TROUGH AND REACH SE TX AND LA LATE TNGT/EARLY SUN.

AT THE SFC...LOOSELY ORGANIZED LEE LOWS NOW IN PLACE OVER THE CNTRL
AND SRN HIGH PLNS SHOULD GRADUALLY CONSOLIDATE OVER W CNTRL TX LATER
TODAY. THIS LOW SHOULD THEN MOVE/DEVELOP ENE INTO SRN AR/NRN LA BY
12Z SUN AS ASSOCIATED WARM FRONT EXTENDING TO ITS E/SE BECOMES
BETTER-DEFINED AND ADVANCES NEWD INTO WRN/SRN MS.

CONTINUED LOW-LVL MOISTENING AHEAD OF CONSOLIDATING SFC LOW...AND
CONTINUED E/NE ADVANCE OF LEAD UPR IMPULSE...WILL LEAD TO INCREASING
TSTM COVERAGE OVER PARTS OF TX AND OK TODAY. THIS ACTIVITY WILL
LIKELY FURTHER EXPAND IN COVERAGE AND STRENGTH EWD INTO
AR...LA...AND MS THROUGH EARLY SUN...WITH AN INCREASING RISK FOR SVR
WEATHER.

...SRN PLNS/ARKLATEX...TODAY INTO TNGT...
E/NE MOTION OF W TX UPR TROUGH...AND CONTINUED MOISTENING TO ITS
E...WILL LIKELY FOSTER INCREASING COVERAGE OF TSTMS FROM MUCH OF OK
SW AND SEWD INTO CNTRL AND ERN TX TODAY THROUGH TNGT. GIVEN
RELATIVELY STEEP MID-LVL LAPSE RATES AND 850 MB DEWPOINTS RISING TO
AOA 12 C...SETUP COULD YIELD A FEW STORMS WITH SVR HAIL GIVEN 40 KT
SW TO WSWLY CLOUD-LAYER SHEAR.

CLOUDS WILL LIMIT SFC HEATING OVER MUCH OF THE REGION. BUT GIVEN
CURRENT SFC AND SATELLITE DATA...HEATING MAY BE SUFFICIENT AHEAD OF
AFOREMENTIONED SFC WAVE TO INITIATE SCTD STORMS IN THE NRN HILL
COUNTRY OF TX LATER THIS AFTN. THIS ACTIVITY MAY THEN CONSOLIDATE
INTO A SMALL CLUSTER OR TWO AND TRACK E/NEWD INTO N CNTRL OR NE
TX...WITH SOME RISK FOR SVR HAIL AND/OR WIND.

OTHER STORMS MAY FORM SOMEWHAT FARTHER S IN THE HILL COUNTRY AND EWD
TOWARD THE WACO AREA...WHERE SOMEWHAT STRONGER DEEP SHEAR AND RICHER
MOISTURE WILL EXIST IN STRENGTHENING/CONFLUENT 925-850 MB FLOW. SUCH
ACTIVITY...WERE IT TO FORM...ALSO SHOULD CONSOLIDATE INTO A
LOOSELY-ORGANIZED CLUSTER...WITH THE STORMS POSSIBLY EXTENDING A SVR
THREAT E/NE INTO THE ARKLATEX AND THE SABINE RVR BY MID-LATE EVE.
GIVEN STRENGTHENING WIND FIELD AND ASCENT... POTENTIAL WOULD EXIST
FOR EMBEDDED SUPERCELLS WITH A CONDITIONAL RISK FOR A TORNADO OR
TWO...IN ADDITION TO DMGG WIND/SVR HAIL.

...LWR MS VLY TNGT/EARLY SUN...
SFC OBSERVATIONS AND BOTH VISIBLE AND DERIVED PW SATELLITE DATA
SUGGEST PRESENCE OF FAIRLY RICH MOISTURE ATTM OVER THE WRN THIRD OF
THE GULF OF MEXICO...WITH SFC DEWPOINTS IN THE UPR 60S F AND PW
AROUND 1.50 INCHES. THESE OBSERVATIONS LEND CREDENCE TO THE IDEA
THAT A SEPARATE AREA OF SHOWERS AND TSTMS WILL FORM ALONG WARM FRONT
CROSSING SRN LA AND MS TNGT/EARLY SUN...SUPPORTED BY STRENGTHENING
CONVERGENCE IN THE 925-850 MB LAYER...AND POSSIBLY BY GLANCING
INFLUENCE OF LOW-AMPLITUDE UPR IMPULSES NOW IN NRN MEXICO.

WHILE TIME OF DAY WILL NOT FAVOR NEAR-SFC DESTABILIZATION...GIVEN
INCREASING LOW-LVL SHEAR /WITH SRH AOA 250 M2 PER S2/... MOISTENING
LOW-LVLS /SFC DEWPOINTS IN THE UPR 60S F/...AND WEAKLY CAPPED
ENVIRONMENT...A CONDITIONAL RISK WILL EXIST FOR EMBEDDED SUPERCELLS
CAPABLE OF TORNADOES AS 700 MB SWLY FLOW INCREASES TO NEARLY 50 KTS
ON SRN FRINGE OF MAIN UPR TROUGH.

...NRN OK AND SRN/ERN KS THIS AFTN INTO TNGT...
N OF MID/UPR-LVL CLOUD SHIELD ASSOCIATED WITH SRN STREAM
DISTURBANCES...SUBSTANTIAL SFC HEATING WILL OCCUR OVER NRN OK AND KS
TODAY. MODEST LOW-LVL MOISTENING ALSO WILL OCCUR OVER THE
REGION...ALONG AND AHEAD OF WEAK COLD FRONT ASSOCIATED WITH CNTRL
PLNS LEE CYCLONE. WHILE DEEP SHEAR AND LARGE-SCALE FORCING FOR
ASCENT WILL BE WEAK...MID-LVL TEMPS WILL BE RELATIVELY COOL /AROUND
MINUS 20 C/...YIELDING MUCAPE OF 1000-1500 J/KG. LOW-LVL
CONVERGENCE/DIFFERENTIAL HEATING MAY BE SUFFICIENT FOR WDLY SCTD
TSTM DEVELOPMENT LATER THIS AFTN INTO TNGT ALONG AND AHEAD OF THE
FRONT. WHILE MOST UPDRAFTS SHOULD REMAIN FAIRLY SHORT-LIVED
...THERMODYNAMIC SETUP SUGGESTS THE POTENTIAL FOR HAIL AND POSSIBLY
LOCALLY DMGG GUSTS IN ANY LONGER-LIVED UPDRAFTS THAT DO FORM.

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