Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 310558
SWODY2
SPC AC 310557

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1257 AM CDT FRI JUL 31 2015

VALID 011200Z - 021200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE CNTRL
PLAINS AND UPPER MS VALLEY REGION...

...THERE IS A MRGL RISK OF SVR TSTMS OVER A PORTION OF THE CNTRL
PLAINS INTO THE UPPER MIDWEST...

...THERE IS A MRGL RISK OF SVR TSTMS OVER A PORTION OF NEW
ENGLAND...

...SUMMARY...
SEVERE THUNDERSTORMS ARE POSSIBLE SATURDAY FROM THE UPPER MIDWEST
INTO THE UPPER MISSISSIPPI VALLEY AND CENTRAL PLAINS. A FEW STRONG
STORMS MAY ALSO OCCUR OVER A PORTION OF NEW ENGLAND.

...SYNOPSIS...

SYNOPTIC UPPER PATTERN WILL REMAIN CHARACTERIZED BY A P-N ANOMALY
WITH ERN U.S. TROUGH EXPECTED TO UNDERGO FURTHER AMPLIFICATION. AT
THE SFC A WARM FRONT WILL MOVE NEWD THROUGH THE MID-UPPER MS VALLEY
WHILE A TROUGH/DRYLINE ADVANCES EWD THROUGH THE NRN/CNTRL PLAINS.

...CNTRL PLAINS THROUGH UPPER MS VALLEY REGION...

PLUME OF STEEPER MID-LEVEL LAPSE RATES WILL SPREAD EWD ABOVE LOW TO
MID 60S BOUNDARY LAYER DEWPOINTS RESIDING IN WARM SECTOR ALONG AND
SOUTH OF NEWD ADVANCING WARM FRONT. THESE PROCESSES AND DIABATIC
WARMING WILL CONTRIBUTE TO A RESERVOIR OF MODERATE INSTABILITY IN
THIS REGION. A FEW THUNDERSTORMS MAY BE ONGOING IN VICINITY OF WARM
FRONT FROM THE CNTRL PLAINS INTO THE MID-MS VALLEY AREA...BUT THIS
ACTIVITY SHOULD DIMINISH DURING THE MORNING. POTENTIAL WILL EXIST
FOR ADDITIONAL STORMS TO INITIATE SATURDAY AFTERNOON...ESPECIALLY
WHERE THE ADVANCING TROUGH/DRYLINE INTERSECTS THE WARM FRONT OVER
SD/NEB. OTHER STORMS MAY DEVELOP OVER THE UPPER MS VALLEY DURING THE
EVENING AS LLJ STRENGTHENS AND AUGMENTS ASCENT ALONG AND NORTH OF
THE WARM FRONT. SLY LOW-LEVEL WINDS VEERING TO NWLY AND
STRENGTHENING WITH HEIGHT WILL RESULT IN 35-45 KT EFFECTIVE BULK
SHEAR SUPPORTIVE OF ORGANIZED STORMS INCLUDING SUPERCELLS. ACTIVITY
MAY GROW UPSCALE INTO ONE OR MORE MCSS OVERNIGHT.

...NEW ENGLAND...

COOL TEMPERATURES ALOFT WITHIN LARGE-SCALE UPPER TROUGH WILL RESIDE
BENEATH MODEST LOW-LEVEL MOISTURE...AND THE ATMOSPHERE WILL UNDERGO
DESTABILIZATION AS SFC HEATING COMMENCES. THUNDERSTORMS ARE EXPECTED
TO DEVELOP WITHIN WEAKLY CAPPED WARM SECTOR AS THE BOUNDARY LAYER
DESTABILIZES DURING THE AFTERNOON. EFFECTIVE SHEAR FROM 35-45 KT
SUGGEST A FEW OF THE STORMS MAY DEVELOP UPDRAFT ROTATION WITH A
THREAT FOR LARGE HAIL. HAVE INTRODUCED A 5% SEVERE PROBABILITY AREA
FOR THIS REGION...BUT AN UPGRADE TO SLIGHT RISK MIGHT BE NEEDED IN
FUTURE UPDATES.

..DIAL.. 07/31/2015




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