[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 170553
SWODY1
SPC AC 170551

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1251 AM CDT MON JUL 17 2006

VALID 171200Z - 181200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VLY NEWD INTO
THE CNTRL GRTLKS REGION...

...SYNOPSIS...
UPPER RIDGE AXIS IS EXPECTED TO REMAIN STRONG ACROSS THE MAJORITY OF
THE COUNTRY ON MON.  A TWO STREAM FLOW WILL EXIST ALONG THE NRN
PERIPHERY OF THE RIDGE WITH THE STRONGEST NRN STREAM SKIRTING THE
GRTLKS AND NRN NEW ENGLAND REGIONS...WITH A WEAKER SUBTROPICAL
STREAM ARCING FROM THE NRN ROCKIES TO THE MIDWEST.  A COUPLE OF
SHORTWAVE TROUGHS WILL BE THE IMPETUS FOR POSSIBLE SEVERE TSTMS MON
AFTN/NIGHT.  NRN STREAM IMPULSE...NOW OVER SRN MANITOBA...WILL DIG
SEWD THROUGH THE GRTLKS REGION BY MON AFTN...THEN APPROACH NRN NEW
ENGLAND BY 12Z TUE.  MEANWHILE...A SUBTROPICAL WAVE OVER THE UPPER
MS VLY AT THE START OF THE PERIOD WILL MOVE ESEWD INTO THE CORN BELT
MON AFTN...THEN THE MIDWEST BY EARLY TUE.

...UPPER MS VLY NEWD INTO THE CNTRL GRTLKS REGION...
HIGH-BASED TSTMS NOW DEVELOPING ACROSS PORTIONS OF ERN SD AND MN ARE
LIKELY TO SPREAD EWD INTO THE UPPER MS VLY BY 12Z...AND SHOULD
WEAKEN MON MORNING AS THE LLJ RELAXES.

THE PRIMARY SEVERE THREAT WILL DEVELOP MON AFTN/EVE.  PLUME OF HOT
TEMPERATURES WILL BE MAINTAINED ALONG/AHEAD OF THE SEWD MOVING COLD
FRONT ASSOCIATED WITH THE NRN STREAM IMPULSE.  GIVEN BOUNDARY LAYER
DEW POINTS BEING MAINTAINED AOA 65 DEG F...MLCAPES WILL RANGE FROM
2000-4000 J PER KG.

AS STRONGER MID-LEVEL HEIGHT FALLS/COOLING SPREAD SEWD ACROSS LAKE
SUPERIOR...TSTM WILL INITIATE ALONG THE COLD FRONT FROM UPPER MI AND
BACKBUILD SWWD INTO PARTS OF WI BY MID-AFTN MON.  VERTICAL SHEAR
WILL BE SUFFICIENT FOR SUPERCELLS...BUT EVOLUTION INTO LINE SEGMENTS
WILL BE FAVORED.  GIVEN UNIDIRECTIONAL WLY FLOW...BOW ECHOES ARE
POSSIBLE WITH DAMAGING WINDS AND LARGE HAIL. THIS ACTIVITY WILL MOVE
ESEWD INTO SRN ONT AND PARTS OF LWR MI DURING MON EVE AND PROBABLY
WEAKEN OVERNIGHT AS THE PRIMARY UPPER FORCING MOVES EWD INTO CANADA.


MEANWHILE...A SEPARATE CLUSTER OF TSTMS IS LIKELY TO FORM ACROSS
PARTS OF IA MON AFTN.  CINH WILL BE GREATER THAN FARTHER NE...BUT
VERY HOT TEMPERATURES AND PRESENCE OF A SUB-TROPICAL DISTURBANCE
MOVING THROUGH THE REGION SHOULD BE FAVORABLE FOR SCT TSTMS.  GIVEN
MAGNITUDE OF LAPSE RATES/INSTABILITY...STORMS WILL GROW RAPIDLY AND
SUPERCELLS WILL BE POSSIBLE WITH LARGE HAIL.  ACTIVITY COULD EVOLVE
INTO AN MCS DURING THE EVENING...AND ACCELERATE EWD INTO SRN WI AND
NRN IL OVERNIGHT WITH A DAMAGING WIND THREAT.

...SWRN DESERTS...
UPPER LEVEL LOW WILL CONTINUE TO ROTATE WWD THROUGH SONORA/SRN AZ
INTO SRN CA MON INTO TUE.  ENHANCED ELY FLOW ALONG NRN PERIPHERY OF
THIS FEATURE WILL CONTINUE ACROSS THE SWRN DESERTS.  TSTMS WILL
LIKELY FORM OVER THE RIM AND ACROSS THE LWR DESERTS TOWARD THE LWR
CO RVR VLY MON AFTN/EVE.  ISOLD DAMAGING WINDS WILL BE POSSIBLE. 
SERN AZ MAY AGAIN SEE AFTN DRYING OF THE BOUNDARY LAYER IF THE
LOW-LEVEL AMBIENT FLOW REGIME OVERCOMES THE DIURNAL CYCLE.  THIS
WOULD TEND TO REDUCE THE OVERALL CONVECTIVE/SEVERE THREATS OVER THAT
AREA.

...GULF COASTAL REGION...
WEAK E-W ORIENTED UPPER SHEAR AXIS WILL REMAIN ALONG THE GULF
COASTAL REGION ON MON. GIVEN A WEAK LOW-LEVEL CONVERGENCE
ZONE...PRESENCE OF VERY HIGH PRECIPITABLE WATER VALUES AND HOT
CONDITIONS...TSTM WILL BE LIKELY FROM PARTS OF ERN TX EWD TO NRN FL.
 WEAK TROPOSPHERIC FLOW WILL FAVOR MULTICELL STORM CLUSTERS THAT
WILL LIKELY PULSE TO NEAR SEVERE LEVELS WITH DAMAGING WINDS THE
PRIMARY SEVERE RISK. ACTIVITY WILL BE LARGELY TIED TO THE DIURNAL
CYCLE AND WEAKEN DURING THE MID-EVENING.

..RACY/JEWELL.. 07/17/2006