[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 281303
SWODY1
SPC AC 281301

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0801 AM CDT THU OCT 28 2004

VALID 281300Z - 291200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 SW
FOD 50 E SUX FSD 20 WSW ATY 60 NE ABR 20 ESE FAR 30 SSE BJI 25 NE
BRD 55 E STC 30 NNE MCW 35 S MCW 35 SW FOD.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 60 E ANJ 20 NE CMH 15
ESE CRW 15 S SAV ...CONT... 30 SE JAX 60 N PIE ...CONT... 35 SSE MOB
20 WSW GWO 10 NNE PBF 30 NW HOT 20 ESE ADM 40 WNW DRT ...CONT... 60
SSW GDP 45 W AMA 15 W RSL 15 SE EAR 15 NNW LBF 15 S SNY 40 SE ALS 30
W GUP EED 60 NE DAG 35 NE EKO 55 SSW BOI 80 SSE S80 LVM 45 NNW DIK
65 N DVL.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE ERN
DAKOTAS...MN AND NRN IA...

...UPPER MS VALLEY AND CNTRL PLAINS...
A LARGE ERN US UPPER-LEVEL RIDGE WILL REMAIN IN PLACE TODAY. A
SHORTWAVE TROUGH EMBEDDED IN SWLY FLOW ALOFT CURRENTLY ACROSS THE
HIGH PLAINS WILL APPROACH THE UPPER MIDWEST TODAY AND THIS WILL
PROVIDE LARGE-SCALE ASCENT TO SUPPORT ONGOING CONVECTION MOVING
ENEWD ACROSS MN AND IA THIS MORNING. SEVERE STORMS WILL BE MOST
LIKELY FARTHER WEST ALONG THE INSTABILITY AXIS THIS AFTERNOON BEHIND
THE INITIAL CONVECTION.

SFC ANALYSIS CURRENTLY SHOWS A MOIST AXIS WITH 60+ SFC DEWPOINTS
EXTENDING NWD ACROSS KS INTO CNTRL NEB. AS THE LOW-LEVEL JET SHIFTS
EWD...THIS MOISTURE WILL ADVECT NNEWD INTO ERN SD AND WRN MN WHERE
MLCAPE VALUES SHOULD REACH 1000 J/KG BY AFTERNOON. LOW-LEVEL
CONVERGENCE WILL INCREASE ALONG A NWD MOVING WARM FRONT IN ERN SD
AND WRN IA THIS AFTERNOON. THIS COMBINED WITH INCREASED FORCING FROM
AN APPROACHING SHORTWAVE SHOULD CAUSE STORMS TO INITIATE ALONG THE
WARM FRONT. A STRONG DEEP LAYER SHEAR ENVIRONMENT IS CURRENTLY IN
PLACE AND THIS WILL MAKE SUPERCELL DEVELOPMENT LIKELY AS STORMS
SPREAD ENEWD ACROSS THE REGION. FORECAST SOUNDINGS IN SW MN AT 21Z
SHOW LOOPED HODOGRAPHS WITH 0-1 KM SHEAR VALUES OF 25 TO 30 KTS.
THIS SHOULD BE FAVORABLE FOR A FEW TORNADOES WITH THE STRONGER
SUPERCELLS THAT DEVELOP. LAPSE RATES ARE FORECAST TO REMAIN MARGINAL
BUT WET BULB ZERO HEIGHTS OF 9000 TO 11000 FEET WILL BE FAVORABLE
FOR HAIL FORMATION. IN ADDITION...50 KTS OF FLOW AT 500 MB SHOULD
RESULT IN A FAST STORM MOVEMENT WHICH WOULD SUPPORT WIND DAMAGE WITH
BOWING SEGMENTS.

AS THE LEFT EXIT REGION OF AN APPROACHING MID-LEVEL JET MOVES ACROSS
THE UPPER MS VALLEY...STORM COVERAGE WILL INCREASE THIS EVENING.
THIS COULD RESULT IN MCS FORMATION AS A SHORTWAVE TROUGH MOVES
QUICKLY INTO THE GREAT LAKES REGION TONIGHT. HOWEVER...THE SYSTEM
WILL MOVE AWAY FROM THE INSTABILITY AXIS TONIGHT AND THE SEVERE
THREAT WILL LIKELY DECREASE BY MIDNIGHT ACROSS THE REGION.

...SRN PLAINS...
OBJECTIVE ANALYSIS CURRENTLY SHOWS AN AXIS OF INSTABILITY FROM KS
EXTENDING SWWD ACROSS WRN OK INTO WCNTRL TX. FAIRLY DRY AIR AT
MID-LEVELS AND ONLY SCATTERED CLOUDS WILL ALLOW RELATIVELY STRONG
SFC HEATING IN THIS REGION THIS AFTERNOON. MLCAPE VALUES SHOULD
REACH 1500 TO 2500 J/KG AND A FEW STORMS SHOULD INITIATE ALONG A
PRE-FRONTAL TROUGH EXTENDING SWWD FROM CNTRL KS TO THE TX PANHANDLE.
THE STORMS SHOULD TRACK ENEWD INTO THE MOIST AXIS AND COULD APPROACH
SEVERE LEVELS LATE THIS AFTERNOON.

LARGE-SCALE ASCENT WILL BE WEAK ACROSS THE REGION AND THIS SHOULD
KEEP CONVECTIVE COVERAGE ISOLATED. STORM STRENGTH WILL BE CLOSELY
TIED TO THE AMOUNT OF INSTABILITY DUE TO THE RELATIVELY WEAK DEEP
LAYER SHEAR THAT SHOULD BE IN PLACE. FORECAST SOUNDINGS SHOW 0-6 KM
SHEAR VALUES SHOULD BE AROUND 30 KT AND THIS WILL BE SUFFICIENT FOR
MARGINALLY SEVERE MULTICELL STORMS. AS THE STORMS MOVE INTO THE
LOW-LEVEL JET EARLY THIS EVENING...STEEP MID-LEVEL LAPSE RATES AND
THE MODERATE INSTABILITY WILL MAKE HAIL OR MARGINAL WIND DAMAGE
POSSIBLE WITH THE STRONGER STORMS. THE STORMS SHOULD WEAKEN QUICKLY
THIS EVENING AS INSTABILITY DECREASES ACROSS THE REGION.

..BROYLES/CROSBIE.. 10/28/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.