Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 271626
SWODY1
SPC AC 271625

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1025 AM CST FRI FEB 27 2015

VALID 271630Z - 281200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
SPORADIC...WEAK THUNDERSTORMS ARE POSSIBLE TODAY INTO TONIGHT FROM
THE OREGON COAST SOUTHEAST ACROSS THE GREAT BASIN AND FOUR CORNERS
REGIONS.

...SYNOPTIC SETUP...
BROAD...INCREASINGLY SPLIT...CYCLONIC FLOW WILL PREVAIL OVER THE LWR
48 THROUGH SAT...DOWNSTREAM FROM PERSISTENT NE PACIFIC RIDGE. STRONG
SHORTWAVE TROUGH COMPLEX NOW CENTERED OVER THE WA/ORE CST SHOULD
FURTHER AMPLIFY AS IT CONTINUES GENERALLY SWD JUST OFF THE ORE/NRN
CA CST...INDUCING WEAK HEIGHT RISES DOWNSTREAM ACROSS THE S CNTRL
U.S.

EXPANSIVE...COLD...LOW-LVL ANTICYCLONE WILL CONTINUE TO MINIMIZE
TSTM POTENTIAL E OF THE RCKYS. RELATIVELY DRY BUT MILDER AIR OF
PACIFIC ORIGIN WILL PERSIST ALONG THE N PACIFIC CST...AND OVER
INTERIOR PARTS OF THE PACIFIC NW AND THE GRT BASIN.

...ORE CST SEWD INTO INTERIOR WRN CONUS TODAY/EARLY TNGT...
MID-LVL COOLING/ASCENT ASSOCIATED WITH SMALLER SCALE DISTURBANCES
WITHIN LARGER-SCALE PACIFIC NW TROUGH...COUPLED WITH AFTN HEATING OF
SUFFICIENTLY WARM/MOIST LOW-LVL ENVIRONMENT...COULD SUPPORT WDLY
SCTD SHOWERS AND ISOLD TSTMS FROM PARTS OF ORE SEWD INTO NE CA AND
MUCH OF NV. DEVELOPMENT IN NV COULD BE ENHANCED BY ASCENT IN
LEFT-EXIT REGION OF 250-MB JET MAX. MODEST MOISTURE WILL LIMIT
BUOYANCY...WITH MLCAPE EXPECTED TO REMAIN AOB 200 J/KG IN MOST
AREAS.

...S FL TODAY...
ELEVATED CONVECTION MAY ATTAIN SUFFICIENT DEPTH TO YIELD AN ISOLD
LIGHTNING STRIKE OR TWO THROUGH EARLY EVE. BUT WITH ELEVATED
WAA/MOISTURE TRANSPORT LIKELY TO LESSEN WITH TIME...AND WITH
ELEVATED THERMAL GRADIENT ALSO LIKELY TO WEAKEN...PROSPECTS FOR A
SUSTAINED TSTM THREAT APPEAR LOW.

..CORFIDI/GRAMS.. 02/27/2015




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