[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 010618
SWODY1
SPC AC 010616

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0116 AM CDT SUN AUG 01 2004

VALID 011200Z - 021200Z

THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 50 ESE
MOT 10 WSW TVF 20 ESE BJI 40 E BRD 25 NNW MSP 20 NW MKT 30 NNW FOD
50 WSW FOD 35 S SUX 15 NNW OFK 35 WNW ATY 20 SE BIS 50 ESE MOT.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 15 NE
MQT 25 S MTW 40 WNW CGX 15 S BRL FNB 30 W LNK 35 SSE 9V9 40 E PIR 35
WSW Y22 35 NNE DIK 55 NNW MOT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SW YUM 35 NNE BLH
40 ESE BIH 25 W NFL 65 SE 4LW 60 SSE LMT 30 SSE RBL 45 NNW UKI 20 E
4BK 25 SSW EUG 15 N PDT 10 NNW 3TH 55 NNW FCA ...CONT... 35 SSW OSC
15 NNE AZO 15 ENE ALN 25 N SZL GRI 20 WSW LBF 30 W GLD 25 NE CAO 45
W ROW 30 NW GDP 15 NNW INK 25 WSW SEP 25 NE GLH 40 S MSL 25 N 5I3 10
N PSB 10 SSW UCA 30 N PBG.

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF SRN/ERN
ND...ERN SD...MUCH OF CENTRAL AND WRN MN...EXTREME NERN NEB AND NWRN
IA...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE DAKOTAS EWD
OVER THE MID MO AND UPPER MS VALLEYS...

...POTENTIAL FOR SIGNIFICANT LARGE HAIL LATE THIS AFTERNOON AND
EVENING ACROSS ERN SD/SWRN MN/EXTREME NERN NEB AND NWRN IA...

...SIGNIFICANT WIND DAMAGE THREAT ACROSS PORTIONS OF ERN ND INTO WRN
AND CENTRAL MN THIS EVENING AND OVERNIGHT...

...SYNOPSIS...
MODELS ARE SIMILAR WITH BUILDING HEIGHTS ACROSS THE CENTRAL PLAINS
TO MID MO VALLEY TODAY...WITH THE STRONGEST WLY MID-LEVEL FLOW
/50-60 KT/ EXTENDING FROM THE DAKOTAS EWD ACROSS THE NRN GREAT LAKES
TO NEW ENGLAND.  A SHORT WAVE TROUGH...CURRENTLY LOCATED OVER SRN BC
IS PROGGED TO MOVE QUICKLY ESEWD TO WRN ND BY 00Z...AND THEN ACROSS
NRN MN TONIGHT.  A WEAK SHORT WAVE TROUGH WILL MOVE ACROSS THE UPPER
MS VALLEY DURING THE FIRST HALF OF THE PERIOD...WHILE A SECOND WEAK
TROUGH APPROACHES ERN SD/WRN MN REGION TOWARD 00Z.  AT THE
SURFACE...AN AREA OF LOW PRESSURE WILL REMAIN OVER SRN SD/NRN NEB. 
A QUASI-STATIONARY BOUNDARY IS EXPECTED TO EXTEND FROM ERN MT ESEWD
ACROSS WRN ND TO ERN SD AND OVER SRN MN/WI.

...DAKOTAS EWD ACROSS MID MO AND UPPER MS VALLEYS...
SEVERAL CLUSTERS OF THUNDERSTORMS ARE EXPECTED TO BE ONGOING AT THE
START OF THE PERIOD FROM ERN NEB NEWD ACROSS IA INTO CENTRAL/SRN WI.
 THIS ACTIVITY MAY PERSIST INTO THE AFTERNOON ACROSS ERN IA AND
PORTIONS OF WI AS A SWLY LLJ NOSING INTO THIS REGION RESULTS IN WAA
CONVECTION.  WEAK SHORT WAVE TROUGH MOVING EWD ACROSS THIS AREA MAY
ALSO PROVIDE SUFFICIENT LARGE SCALE ASCENT FOR THESE THUNDERSTORMS
TO CONTINUE INTO THE AFTERNOON.

MEANWHILE...SURFACE LOW OVER SD WILL AID IN ADVECTING LOWER 70
DEGREE DEWPOINTS NWD INTO ERN SD/SWRN-WEST CENTRAL MN BY THIS
AFTERNOON.  WLY MID-LEVEL FLOW WILL SPREAD STEEP LAPSE RATES ACROSS
THE DAKOTAS AND UPPER MS VALLEY BY 00Z...EFFECTIVELY CAPPING THE AIR
MASS FROM SD/NEB INTO SWRN MN/NWRN IA FOR MUCH OF THE DAY.  SURFACE
HEATING AND CONVERGENCE ALONG THE FRONT IN ERN SD/WRN MN AND A DRY
LINE EXTENDING N-S ACROSS ERN SD IS EXPECTED TO RESULT IN
THUNDERSTORM  DEVELOPMENT BY 00Z OVER THE SRN HALF OF THE MODERATE
RISK.  40-45 KT OF DEEP LAYER SHEAR COMBINED WITH EXTREME
INSTABILITY /MLCAPE AROUND 4000 J/KG/ OVER THIS REGION WILL SUPPORT
SUPERCELLS WITH VERY LARGE HAIL AND ISOLATED TORNADOES.  MODELS
SUGGEST THAT AS A SWLY LLJ STRENGTHENS AGAIN FROM NRN KS INTO
IA...INITIAL ACTIVITY MAY DEVELOP UPSCALE INTO A FORWARD PROPAGATING
MCS ACROSS SRN MN/NRN IA INTO SRN WI TONIGHT.

A SURFACE LOW IS ALSO PROGGED TO DEVELOP ALONG THE FRONT OVER WRN ND
THIS AFTERNOON WITH THE APPROACH OF THE BC SHORT WAVE TROUGH.  STEEP
LAPSE RATES OVER ND COMBINED WITH SURFACE DEWPOINTS IN THE 50S WILL
RESULT IN MLCAPE VALUES OF 500-1000 J/KG.  MODELS SUGGEST
THUNDERSTORMS SHOULD DEVELOP OVER WRN-CENTRAL ND BETWEEN 00-03Z AND
THEN EVOLVE INTO A POTENTIAL BOW ECHO WITH A CONCENTRATED AREA OF
DAMAGING WINDS FROM ERN ND TO WRN/CENTRAL MN TONIGHT.  THIS SCENARIO
SEEMS REASONABLE SINCE THE AIR MASS AHEAD OF THE BOW WILL CONTINUE
TO DESTABILIZE OVERNIGHT AS A SWLY LLJ ADVECTS MOISTURE NNEWD WITH
MODERATE INSTABILITY EXPECTED INTO ERN ND TO CENTRAL MN.

...GREAT BASIN...
STRONG SURFACE HEATING COMBINED WITH MID-LEVEL MOISTURE WILL SUPPORT
THUNDERSTORM DEVELOPMENT OVER THE HIGHER TERRAIN THIS AFTERNOON INTO
THE EVENING.  40 KT OF SLY MID-LEVEL FLOW ON THE ERN PERIPHERY OF
THE CLOSED UPPER LOW OVER NWRN CA SHOULD AID IN SOME STORM
ORGANIZATION...GIVEN 30-35 KT OF DEEP LAYER SHEAR.  MARGINAL
INSTABILITY WILL LIMIT THE SEVERE THREAT...BUT INVERTED-V PROFILES
WILL SUPPORT ISOLATED DAMAGING WINDS.

..PETERS/GUYER.. 08/01/2004

...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.