[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 041735
SWODY2
SPC AC 041734

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1234 PM CDT FRI AUG 04 2006

VALID 051200Z - 061200Z

...THERE IS A SLGT RISK OF SVR TSTMS SATURDAY AFTERNOON AND EARLY
SATURDAY NIGHT FROM THE ERN DAKOTAS INTO MINNESOTA....

...SYNOPSIS...
VIGOROUS MID/UPPER LEVEL LOW/ASSOCIATED SHORTWAVE TROUGH IS FORECAST
TO MOVE FROM SRN SASKATCHEWAN INTO SWRN ONTARIO DURING THE PERIOD. 
MODELS STRENGTHEN THE AMPLITUDE OF THIS TROUGH SLIGHTLY AS IT MOVES
THROUGH THE UPPER MS VALLEY REGION DURING THE AFTERNOON AND EVENING.
 MEANWHILE...STRONG MID/UPPER LEVEL RIDGING WILL REMAINED ANCHORED
FROM THE CENTRAL/SRN ROCKIES EWD INTO THE CAROLINAS.

...NRN PLAINS INTO THE UPPER MS VALLEY...

MODELS GENERATE STRONG DYNAMICS IN ASSOCIATION WITH THE MID/UPPER
LEVEL LOW MOVING THRU SOUTH CENTRAL CANADA ON SATURDAY.  BY
06/00Z...STRONG COLD FRONT WILL EXTEND SWD/SWWD THRU NWRN MN...SERN
ND AND S CENTRAL SD INTO SERN WY.  SSWLY LOW LEVEL JET OF 40-45 KT
WILL EXTEND FROM NERN NEB THRU THE MN ARROWHEAD BY THIS TIME.  THIS
WILL BECOME COUPLED WITH WLY/NWLY MID LEVEL FLOW NEAR 70 KT OVER NRN
ND INTO NWRN MN...AND 250 MB WINDS NEAR 100 KT OVER EXTREME SRN
MANITOBA INTO SWRN ONTARIO.  THIS WILL CREATE FAVORABLE VERTICAL
SHEAR PROFILES TO SUPPORT ROTATING STORMS OVER PARTS OF NRN MN BY
SATURDAY AFTN. IN ADDITION...STRONG 700 MB DRY AIR INTRUSION IS
EXPECTED TO PUSH ITS WAY OVER ND INTO NWRN MN IN CONJUNCTION WITH
UPPER LEVEL DIVERGENCE WHICH IS EXPECTED TO ENHANCE UVVS ALONG AND
AHEAD OF THE COLD FRONT.

AIR MASS IS FORECAST TO BE QUITE UNSTABLE WITH MODEL LIS BETWEEN -6
AND -10...AND MLCAPE FROM NERN SD INTO W CENTRAL MN BETWEEN 2000 AND
3000 J/KG.  ANALYSIS OF POINT FORECAST SOUNDINGS ACROSS W CENTRAL MN
INDICATE STRONG CAPPING INVERSION INTO THE AFTERNOON THAT WILL
WEAKEN AS FRONTAL BOUNDARY/SQUALL LINE APPROACHES GOING INTO THE
EVENING.  STEEP MID LEVEL LAPSE RATES OF 8-8.5C/KM WILL BE
SUPPORTIVE OF HAIL AND STRONG DAMAGING WINDS.

THUS...STRONG/SEVERE THUNDERSTORMS/SQUALL LINE ARE EXPECTED TO
DEVELOP AFTER MID AFTN ALONG/AHEAD OF THE COLD FRONTAL BOUNDARY. 
THIS ACTIVITY IS EXPECTED TO INTENSIFY GOING INTO THE LATE AFTERNOON
AND EVENING AS IT MOVES INTO VERY UNSTABLE AIR MASS.  OTHER THAN THE
MAIN THREATS OF HAIL AND DAMAGING WINDS...DEEP LAYER SHEAR OF 40-50
KT SUGGESTS THE POSSIBILITY OF SUPERCELLS/TORNADOES ACROSS THE NRN
THIRD OF MN.

...SERN STATES...

MOIST...TROPICAL-LIKE AIR MASS WILL REMAIN IN PLACE ACROSS MUCH OF
THE SERN QUARTER OF THE U.S.  FLOW IS WEAK ACROSS THIS GENERAL AREA
WITH POTENTIAL INSTABILITY BETWEEN 1500 AND 2500 J/KG DURING PERIOD
OF PEAK HEATING.  WIDESPREAD PULSE THUNDERSTORMS WILL BE EXPECTED
AGAIN SATURDAY AFTN AND EARLY SATURDAY NIGHT.  TWO MAIN BOUNDARIES
ARE EVIDENT IN THE MODEL DATA...ONE ACROSS THE TN VALLEY INTO SRN
NC...THE OTHER ALONG THE CENTRAL GULF COAST.  MORE
NUMEROUS...ORGANIZED STORMS ARE POSSIBLE IN THESE AREAS.  MAIN
THREAT WITH THIS ACTIVITY WILL BE WET MICROBURSTS.

..MCCARTHY.. 08/04/2006