Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 011626
SWODY1
SPC AC 011624

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1124 AM CDT FRI AUG 01 2014

VALID 011630Z - 021200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
THUNDERSTORMS...INCLUDING SOME WITH A MARGINAL SEVERE THREAT...WILL
OCCUR OVER THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES...WESTERN
SOUTH DAKOTA INTO NEBRASKA...AND FROM PARTS OF GEORGIA INTO THE
CAROLINAS.

...SYNOPTIC SETUP...
LITTLE CHANGE TO AMPLIFIED WRN RIDGE/ERN TROUGH PATTERN EXPECTED
THROUGH SAT. BROAD ERN TROUGH EXTENDING SSW FROM SLOWLY-PROGRESSIVE
JAMES BAY LOW WILL PERSIST OVER THE OH AND MS VLYS. WITHIN THE
TROUGH...ONE LOW-AMPLITUDE/ELONGATED IMPULSE NOW OVER GA AND THE SRN
APPALACHIANS WILL SHEAR NNE ACROSS THE CAROLINAS TO THE MID-ATLANTIC
CST LATER TODAY/TNGT...WHILE UPSTREAM DISTURBANCE NOW OVER MN
CONTINUES SE INTO THE MID MS VLY. FARTHER W...SATELLITE SHOWS
SEVERAL DISTURBANCES TOPPING THE WRN RIDGE. THE ONE NOW IN ORE
SHOULD DRIFT NEWD AND WEAKEN...WHILE LOOSELY-ORGANIZED FEATURE IN
SRN SK/NE MT CONTINUES ESE INTO THE WRN DAKOTAS.

FEATURES WILL REMAIN VERY WEAK AT THE SFC. SHALLOW SW-NE BOUNDARY
MARKING THE NWRN FRINGE OF WRN ATLANTIC/CARIBBEAN AIR...NOW STALLED
ALONG THE SRN NC CST...SHOULD DRIFT A BIT INLAND ACROSS FAR ERN NC
AND FAR SERN VA TODAY/TNGT IN RESPONSE TO APPROACHING UPR IMPULSE.
OTHERWISE...POORLY-DEFINED LEE TROUGH WILL REMAIN QSTNRY OVER THE
NRN HIGH PLNS.

...GA/CNTRL-ERN CAROLINAS INTO SE VA TODAY/TNGT...
NUMEROUS SHOWERS AND WDLY SCTD TSTMS ARE EXPECTED OVER THE
PIEDMONT/CSTL PLN OF GA...THE CAROLINAS...AND SE VA THROUGH EARLY
SAT. ACTIVITY WILL BE FOSTERED BY ASCENT DOWNSTREAM FROM SHEARING
UPR IMPULSE AND RICH MOISTURE /ESPECIALLY ALONG THE CST...WHERE PW
WILL REMAIN AOA 2 INCHES/. MODEST SFC HEATING AND TIMING OF UPR
IMPULSE SUGGEST COVERAGE/INTENSITY MAY PEAK LATER THIS AFTN INTO
TNGT OVER ERN NC AND SE VA.

LOW-LVL LAPSE RATES WILL REMAIN WEAK OVER MUCH OF THE REGION GIVEN
EXISTING CLOUDS/RAIN. BUT A CORRIDOR OF ENHANCED LOW-LVL DIRECTIONAL
SHEAR...SAMPLED ATTM BY THE MHX VWP...WILL PERSIST NEAR
AFOREMENTIONED FRONT. AS THAT BOUNDARY DRIFTS A BIT NWWD LATER
TODAY...AND AS BAND OF SLIGHTLY STRONGER 700-500 MB FLOW/ASCENT
OVERSPREAD REGION AHEAD OF UPR DISTURBANCE...A FEW SHOWERS/STORMS
MAY ACQUIRE LOW-LVL ROTATION GIVEN CONFLUENT/LOW LCL/MOISTURE-RICH
ENVIRONMENT.

RELATIVELY WEAK BACKGROUND PRESSURE FIELD SHOULD KEEP LOW-LVL
WINDS...AND MAGNITUDE OF DIRECTIONAL SHEAR...FAIRLY MODEST. BUT SOME
POTENTIAL WILL EXIST FOR OCCASIONAL STORM-SCALE
VORTICITY/CONVERGENCE AUGMENTATION. THUS...THERE WILL BE A
CONDITIONAL RISK FOR A COUPLE TORNADOES...EVEN THOUGH THE OVERALL
THREAT STILL APPEARS TOO DISORGANIZED/ISOLD/TRANSIENT TO WARRANT AN
OUTLOOK UPGRADE ATTM. IF AN UPGRADE TO SLGT RISK WERE TO BE REQUIRED
LATER TODAY...IT MOST LIKELY WOULD BE FOR FAR ERN/NERN NC.

FARTHER W/SW...WHERE SFC HEATING WILL BE SOMEWHAT
GREATER...PRECIP-LOADING MAY YIELD A DMGG GUST OR TWO ALONG
SECONDARY WIND SHIFT LINE MOVING E ACROSS CNTRL NC...CNTRL/ERN
SC...AND ERN GA THIS AFTN.

...UPR MS VLY THIS AFTN...
STRONG SFC HEATING WILL OCCUR TODAY BENEATH MN UPR IMPULSE AS IT
CONTINUES SEWD INTO PARTS OF WI/IL AND IA...SUPPORTING WDLY SCTD
AFTN TSTM DEVELOPMENT IN ZONE OF WEAK LOW-LVL CONVERGENCE/MODEST
MOISTURE. MID-LVL LAPSE RATES WILL BE FAIRLY STEEP...SUGGESTING
POTENTIAL FOR HAIL IN STRONGER UPDRAFTS. BUT WEAK SHEAR SHOULD KEEP
ANY SVR THREAT TRANSIENT/ISOLD.

...NRN PLNS THIS AFTN/EVE...
MID-LVL LAPSE RATES/ASCENT WILL INCREASE OVER WRN PARTS OF THE NRN
PLNS TODAY...DOWNSTREAM FROM SK/MT UPR TROUGH. COUPLED WITH STRONG
SFC HEATING...MODEST LOW-LVL MOISTURE /PW .75-1.00 INCH/...AND WEAK
UPLIFT ALONG LEE TROUGH/TERRAIN...SETUP MAY YIELD WDLY SCTD AFTN
STORMS CAPABLE OF STRONG GUSTS AND PERHAPS HAIL GIVEN INVERTED-V SUB
CLOUD LAYER THERMODYNAMIC PROFILES.

..CORFIDI/MOSIER.. 08/01/2014



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