Severe Storm Outlook Narrative (AC)
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
000
ACUS02 KWNS 251731
SWODY2
SPC AC 251730

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT THU AUG 25 2016

VALID 261200Z - 271200Z

...THERE IS A MRGL RISK OF SVR TSTMS OVER PORTIONS OF THE NORTHERN
HIGH PLAINS...

...THERE IS A MRGL RISK OF SVR TSTMS OVER PARTS OF THE CENTRAL
PLAINS AND MID-MISSISSIPPI VALLEY...

...SUMMARY...
ISOLATED SEVERE STORMS ARE EXPECTED ACROSS THE NORTHERN HIGH
PLAINS...AND ACROSS PARTS OF THE CENTRAL PLAINS AND MID-MISSISSIPPI
VALLEY ON FRIDAY.

...SYNOPSIS...
A BROAD UPPER-LEVEL TROUGH WILL EXTEND ACROSS PORTIONS OF THE
ROCKIES/CENTRAL U.S. FRIDAY AFTERNOON...WITH A BELT OF STRONGER
WINDS ASSOCIATED WITH ZONAL FLOW FROM THE GREAT LAKES INTO THE
NORTHEAST U.S.  WITHIN THIS UPPER-LEVEL REGIME...AN IMPULSE WILL
MOVE FROM THE CENTRAL ROCKIES EARLY IN THE DAY EAST/NORTHEAST INTO
CENTRAL PLAINS BY AFTERNOON.  A SURFACE COLD FRONT WILL MOVE
EAST/SOUTHEAST ACROSS THE NORTHEAST AND MID-ATLANTIC REGION
FRIDAY..WHILE THE WESTERN EXTENSION OF THE FRONT ACROSS THE CENTRAL
PLAINS BEGINS TO LIFT NORTHWARD DURING THE DAY.

...PORTIONS OF CENTRAL PLAINS/MID-MISSISSIPPI VALLEY...
ONGOING STORMS/RESIDUAL CLOUD COVER FROM DAY 1 CAST SOME UNCERTAINTY
ON THE LOCATION AND TIMING FOR SEVERE STORMS LATER FRIDAY.
OVERALL...THE COMPOSITE FRONTAL BOUNDARY IS EXPECTED TO EXTEND
GENERALLY EAST-WEST ACROSS MO/KS EARLY IN THE DAY...AND LIFT
NORTHWARD WITH TIME AS THE CENTRAL ROCKIES UPPER-LEVEL IMPULSE LIFTS
NORTHEAST INTO THE CENTRAL PLAINS. DIFFERENTIAL HEATING SHOULD
RESULT IN POCKETS OF MODERATE-STRONG SURFACE-BASED INSTABILITY
DURING THE AFTERNOON.  MODEST MID-LEVEL FLOW WILL RESULT IN
DEEP-LAYER SHEAR AVERAGING 25-LOCALLY 35 KTS.  DAYTIME/DIFFERENTIAL
HEATING COMBINED WITH WEAK LARGE-SCALE ASCENT WITH THE UPPER-LEVEL
IMPULSE WILL RESULT IN AN INCREASE IN THUNDERSTORM COVERAGE WITHIN
AN ENVIRONMENT SUPPORTIVE OF ORGANIZED STRONG/SEVERE STORMS.  WITH
TIME STORMS SHOULD EVOLVE INTO A FEW CLUSTERS.

...NORTHERN HIGH PLAINS....
RELATIVELY COOL MIDLEVEL TEMPERATURES WILL EXIST OVER THE AREA AND
COMBINE WITH A CORRIDOR OF LOWER/MID 50S F DEWPOINTS TO RESULT IN
MARGINAL INSTABILITY BY AFTERNOON.  MID-LEVEL FLOW OF 30-35 KTS WILL
BE SUFFICIENT FOR ISOLATED STRONG/SEVERE STORMS THROUGH EARLY
EVENING.

...NORTHEAST U.S....
A FEW THUNDERSTORMS WILL BE POSSIBLE EARLY IN THE DAY IN ASSOCIATION
WITH A COLD FRONT MOVING EASTWARD TOWARDS THE COAST.  THE EARLY DAY
TIMING SUGGESTS A LOW SEVERE POTENTIAL WITH LIMITED TIME FOR
DESTABILIZATION...HOWEVER LOW SEVERE PROBABILITIES MAY BE WARRANTED
IN LATER OUTLOOKS IF A SLOWER FRONTAL MOTION/GREATER INSTABILITY
SCENARIO ULTIMATELY EVOLVES.

..BUNTING.. 08/25/2016

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.