SWODY2
SPC AC 270559
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT MON AUG 27 2007
VALID 281200Z - 291200Z
..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL
PLAINS AND UPPER MIDWEST...
..CNTRL PLAINS AND UPPER MIDWEST...
A LOW-AMPLITUDE UPPER-LEVEL TROUGH OVER THE NRN HIGH PLAINS LATE
TONIGHT WILL MOVE EWD INTO THE NRN PLAINS TUESDAY. AT THE SFC...A
COLD FRONT IS FORECAST TO MOVE SWD INTO THE UPPER MIDWEST AND CNTRL
PLAINS. EVEN THOUGH LARGE-SCALE ASCENT WILL BE RELATIVELY
WEAK...MODEL FORECASTS INCREASE LOW-LEVEL CONVERGENCE ALONG THE
BOUNDARY WHICH COMBINED WITH SFC HEATING SHOULD RESULT IN SCATTERED
THUNDERSTORM INITIATION DURING THE AFTERNOON FROM NRN KS EXTENDING
NEWD ACROSS SE NEB...IA INTO WI. THE NAM...GFS AND NAMKF AGREE WITH
DEVELOPING MODERATE INSTABILITY ALONG AND AHEAD OF THE BOUNDARY FROM
NEAR OMAHA NEB EXTENDING NEWD ACROSS IA AND SRN WI. ALTHOUGH MODEL
FORECASTS DISAGREE ON THE AMOUNT OF VERTICAL SHEAR VARYING FROM 30
TO 50 KT...FORECAST SOUNDINGS DO SHOW VERY STEEP LOW-LEVEL LAPSE
RATES AND 20 TO 25 KT OF LOW-LEVEL FLOW WHICH SHOULD BE SUFFICIENT
FOR AN ISOLATED WIND DAMAGE THREAT. THE WIND DAMAGE THREAT SHOULD BE
GREATEST WITH ORGANIZED BOWING LINE-SEGMENTS IN THE LATE AFTERNOON
AND EARLY EVENING AS LOW-LEVEL FLOW INCREASES.
..CNTRL HIGH PLAINS...
FURTHER WEST ACROSS THE CNTRL HIGH PLAINS...FORECAST INSTABILITY IS
CONSIDERABLY WEAKER THAN ACROSS THE UPPER MIDWEST.
HOWEVER...SCATTERED THUNDERSTORMS SHOULD STILL INITIATE ALONG THE
BOUNDARY AND IN THE HIGHER TERRAIN OF ECNTRL CO AND SE WY. FORECAST
SOUNDINGS ACROSS THE REGION TUESDAY AFTERNOON SUGGEST LAPSE RATES
WILL BE STEEP AND MODERATE VERTICAL SHEAR WILL BE IN PLACE. AS A
RESULT...A MARGINAL SEVERE THREAT SHOULD EXIST NEAR PEAK HEATING IN
AREAS WHERE INSTABILITY IS LOCALLY MAXIMIZED.
.BROYLES.. 08/27/2007
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.
No comments:
Post a Comment