Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS01 KWNS 010533
SWODY1
SPC AC 010532

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1232 AM CDT SAT OCT 01 2016

VALID 011200Z - 021200Z

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS CNTRL MT...

...SUMMARY...
A FEW STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS PORTIONS OF
CENTRAL MONTANA THIS AFTERNOON AND EVENING.

...SYNOPSIS...
MATURE CYCLONE...WHICH HAS REMAINED LARGELY STATIONARY OVER THE OH
VALLEY DURING THE PAST FEW DAYS...IS EXPECTED TO DRIFT NWD TOWARDS
LOWER MI. VERTICALLY STACKED CHARACTER OF THE CYCLONE AND ITS
GENERAL STAGNATION OVER THE PAST FEW DAYS HAS RESULTED IN A
RELATIVELY HOMOGENEOUS AIRMASS ACROSS THE REGION. THIS AIRMASS IS
CHARACTERIZED BY RECYCLED LOW-LEVEL MOISTURE AND NEAR-NORMAL
TEMPERATURES BUT COLD MID-LEVEL TEMPERATURES NEAR THE CENTER OF THE
UPPER LOW WILL CONTRIBUTE TO MODEST INSTABILITY /MLCAPE AROUND 500 J
PER KG/ AND ISOLATED TSTM DEVELOPMENT.

FARTHER W...LEAD SHORTWAVE TROUGH WILL PIVOT THROUGH AN UPPER TROUGH
MOVING SLOWLY INTO THE PACIFIC NW...REACHING THE NRN ROCKIES BY THE
AFTERNOON AND CONTINUING INTO ALBERTA BY EARLY SUNDAY MORNING.
ASSOCIATED COLD FRONT WILL MOVE ACROSS THE REGION JUST AHEAD OF THIS
SHORTWAVE TROUGH...PUSHING INTO CNTRL MT BY THE LATE AFTERNOON.

...CNTRL MT...
STRONG FORCING FOR ASCENT...PROVIDED BY BOTH THE APPROACHING
SHORTWAVE TROUGH AND COLD FRONT...WILL COUPLE WITH MODEST LOW-LEVEL
MOISTURE AND COOL TEMPERATURES ALOFT TO PROVIDE THE IMPETUS FOR
AFTERNOON TSTMS. STRONG FLOW ALOFT WILL CONTRIBUTE TO STRONG
VERTICAL SHEAR AND THE POTENTIAL FOR SOME STRONGER STORMS CAPABLE OF
DAMAGING WIND GUSTS...PARTICULARLY IN AREAS WHERE DAYTIME HEATING
FOSTERS STEEP LOW-LEVEL LAPSE RATES. GIVEN THE COOL TEMPERATURES
ALOFT...SOME HAIL IS ALSO POSSIBLE.

..MOSIER/COHEN.. 10/01/2016

$$



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