SPC AC 171720
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1220 PM CDT THU APR 17 2008
VALID 181200Z - 191200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER MS VALLEY...
...LOWER MS VALLEY...
A HIGHLY MERIDIONAL UPPER-LEVEL TROUGH IS FORECAST TO MOVE EWD
ACROSS THE PLAINS STATES TONIGHT AND CLOSE OFF ACROSS THE
MID-MISSOURI VALLEY FRIDAY. AT THE SFC...A COLD FRONT WILL ADVANCE
EWD ACROSS THE SRN PLAINS LATE TONIGHT REACHING THE OZARK PLATEAU
AROUND MIDDAY. AHEAD OF THE FRONT...A MOIST AXIS WILL BE IN PLACE
WITH 60 TO 65 F SFC DEWPOINTS REMAINING ACROSS LA AND SW MS ALLOWING
FOR A SMALL POCKET OF MODERATE INSTABILITY BY EARLY AFTERNOON.
THUNDERSTORMS SHOULD INITIATE ALONG THE FRONT AND MOVE EWD ACROSS LA
INTO SRN AND CNTRL MS BY LATE AFTERNOON. THE NAM AND GFS SOLUTIONS
ARE IN VERY GOOD AGREEMENT CONCERNING THIS SCENARIO AND CONFIDENCE
IS FAIRLY HIGH THAT A SMALL MCS WILL DEVELOP AND MOVE EWD ACROSS THE
REGION.
CONCERNING THE SEVERE WEATHER POTENTIAL...A 65 TO 75 KT MID-LEVEL
JET IS FORECAST TO ROUND THE BASE OF THE UPPER-LEVEL TROUGH AND MOVE
EWD ACROSS THE LOWER MS VALLEY FRIDAY. THIS FEATURE WILL INCREASE
VERTICAL SHEAR PROFILES FROM WEST TO EAST BECOMING FAVORABLE SEVERE
STORMS FRIDAY AFTERNOON. THE SHEAR ENVIRONMENT SHOULD BE SUPPORTIVE
FOR A FEW SUPERCELLS CAPABLE OF PRODUCING HAIL AND WIND DAMAGE. A
TORNADO THREAT MAY ALSO DEVELOP WITH THE MORE PERSISTENT SUPERCELLS.
HOWEVER...THE SEVERE WEATHER COVERAGE SHOULD BE HIGHLY DEPENDENT ON
HOW MUCH INSTABILITY DEVELOPS ACROSS THE REGION FRIDAY AFTERNOON.
FURTHER NORTH IN THE OZARKS AND MID-MS VALLEY...SHALLOW CONVECTION
IS FORECAST TO DEVELOP DUE TO A BAND OF FOCUSED LARGE-SCALE ASCENT
JUST AHEAD OF THE UPPER-LEVEL TROUGH. LIMITED INSTABILITY AND A
RELATIVELY DRY BOUNDARY LAYER EVIDENT ON FORECAST SOUNDINGS ACROSS
ERN MO AND NE AR SHOULD KEEP THE CONVECTION BELOW SEVERE LIMITS.
..BROYLES.. 04/17/2008
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0800Z
|
