Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 271628
SWODY1
SPC AC 271626

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1126 AM CDT FRI MAY 27 2016

VALID 271630Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL AND SRN
PLNS...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF CNTRL AND SE
TX...

...THERE IS A MRGL RISK OF SVR TSTMS FROM S CNTRL TX NNE INTO THE
LWR MO AND MID-MS VLYS...

...SUMMARY...
THUNDERSTORMS WITH A RISK FOR HAIL AND LOCALLY DAMAGING WIND WILL BE
SCATTERED FROM WESTERN AND CENTRAL OKLAHOMA INTO KANSAS AND PARTS OF
THE LOWER MISSOURI VALLEY. A CONDITIONAL THREAT FOR SEVERE STORMS
ALSO WILL EXIST OVER PARTS OF CENTRAL AND SOUTHEAST TEXAS.

...SYNOPTIC SETUP...
ERN CO UPR LOW EXPECTED TO DRIFT E INTO WRN KS BY THIS EVE...AND ENE
INTO S CNTRL NEB TNGT...AS RIDGE REMAINS STNRY OFF THE MID-ATLANTIC
CST. SHORTWAVE TROUGH NOW ROUNDING BASE OF THE LOW WILL ASSUME A
NEGATIVE TILT AS IT CONTINUES E INTO CNTRL OK THIS EVE...AND THEN NE
ACROSS THE MO OZARKS EARLY SAT.

SYNOPTIC-SCALE FRONTS/SFC FEATURES WILL REMAIN COMPARATIVELY WEAK. A
FAIRLY WELL-DEFINED LOW WILL...HOWEVER...TRACK SLOWLY ENE ACROSS KS
TODAY/TNGT IN ASSOCIATION WITH THE UPR LOW. A DIFFUSE/FRACTURED
STNRY FRONT WILL PERSIST NEWD FROM THE LOW INTO THE UPR GRT LKS.
COLD FRONT/DRY LINE SEGMENTS TRAILING S AND SSW FROM THE LOW SHOULD
BECOME BETTER DEFINED TODAY IN RESPONSE TO SFC HEATING AND EJECTION
OF UPR TROUGH. FARTHER S...COMPOSITE OUTFLOW BOUNDARIES FROM
OVERNIGHT MCSS WILL SERVE AS LOW-LVL SOURCES OF ASCENT FROM W CNTRL
TX ESE TO THE MIDDLE AND UPR TX GULF CST.

...OK/KS/NEB THIS AFTN/EVE...
FORCING FOR ASCENT AND SFC HEATING IN DRY SLOT ROTATING NEWD AROUND
CO LOW WILL FURTHER DESTABILIZE PARTS OF THE CNTRL AND SRN PLNS
TODAY. ALTHOUGH BOUNDARY LAYER DEWPOINTS WILL BE SOMEWHAT REDUCED
RELATIVE TO RECENT DAYS GIVEN ANTECEDENT STORMS...AMPLE MOISTURE
WILL EXIST FOR STRONG UPDRAFTS GIVEN EXPECTED COOLING ALOFT /500 MB
TEMPS FALLING TO AOB MINUS 14C/.

MESOSCALE NATURE OF EJECTING UPR TROUGH AND ITS RELATIVELY FAST
FORWARD MOVEMENT MAKE IT DIFFICULT TO GENERALIZE THE WIND FIELD.
PROFILES WILL VARY CONSIDERABLY IN SPACE/TIME ACROSS THE
REGION...BUT SHOULD BE FAIRLY MERIDIONAL /ESPECIALLY IN NEB-NRN KS/.
IN ADDITION...SOME DEGREE OF VEER/BACK PATTERN IN THE VERTICAL
APPEARS LIKELY. NEVERTHELESS...PROFILES WILL BE MORE THAN SUFFICIENT
FOR SUSTAINED UPDRAFTS. A COMPLEX MIX OF BROKEN LINES/SMALL CLUSTERS
CONTAINING EMBEDDED SUPERCELLS AND OTHER SUSTAINED STORMS
ALONG/AHEAD OF THE COLD FRONT/DRY LINE APPEARS TO BE THE MOST LIKELY
SCENARIO. A FEW STORMS ALSO MAY FORM ALONG STNRY FRONT SEGMENTS
EXTENDING ENE ACROSS NEB/IA AND NRN MO. AS HEATING BOOSTS MLCAPE TO
1500-2000 J/KG...THE STORMS WILL BE CAPABLE OF LARGE HAIL...DMGG
WIND...AND POSSIBLY A COUPLE TORNADOS...ESPECIALLY DURING THE EARLY
STAGES OF DEVELOPMENT.

...CNTRL/SE TX THIS AFTN INTO TNGT...
A CONDITIONAL THREAT FOR SVR STORMS WILL EXIST THIS AFTN INTO TNGT
ALONG STALLED/STALLING COMPOSITE OUTFLOW BOUNDARIES EXTENDING FROM
CNTRL TX ESE THROUGH THE TX HILL COUNTRY INTO THE AREA N OF HOU.
SATELLITE SUGGESTS THAT THIS CORRIDOR WILL BE...AT MOST...JUST
GLANCED BY EJECTING UPR IMPULSE. BUT IT DOES NOT APPEAR THAT REGION
WILL EXPERIENCE RIDGING ALOFT. 35-45 KT WSWLY 700-500 MB FLOW WILL
BE AMPLE FOR UPDRAFT ORGANIZATION/SUSTENANCE GIVEN PERSISTENT 25-30
NEAR-SFC SLY FLOW. WITH WARM SECTOR DEWPOINTS INTO THE MID 60S TO
LOW 70S /1.50-2.00 INCH PW/...AND STEEP MID-LVL LAPSE RATES
ASSOCIATED WITH EML SWEEPING ENE IN BASE OF THE CO LOW...SFC HEATING
WILL YIELD MUCAPE ON THE ORDER OF 4000 J/KG. SUCH STRONG BUOYANCY IN
THE PRESENCE OF MODERATE SPEED/DIRECTIONAL SHEAR AND A SOURCE OF
LOW-LVL UPLIFT SUGGESTS AT LEAST A CONDITIONAL RISK FOR SUPERCELLS
WITH LARGE HAIL...DMG WIND...AND POSSIBLY A COUPLE  TORNADOES IF EML
CAP IS BREACHED. IF STORMS DO INDEED FORM...UPSCALE GROWTH INTO AN
E-MOVING MCS APPEARS LIKELY BY TNGT.

...NRN NY/NW NEW ENGLAND...
A FEW STRONG AFTN STORMS COULD FORM OVER THE ADIRONDACKS AND THE
MTNS OF ADJACENT VT/NH AS SFC HEATING STEEPENS LOW-LVL LAPSE RATES
IN MOIST AIR SW OF WEAK WARM FRONT. DEEP SHEAR/FORCING FOR ASCENT
WILL...HOWEVER...BE WEAK...AND WARM LAYER AROUND 500 MB SHOULD LIMIT
STORM SUSTENANCE/STRENGTH.

..CORFIDI/COOK.. 05/27/2016

$$


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