DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 302002
SWODY1
SPC AC 302000

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT SAT JUN 30 2007

VALID 302000Z - 011200Z

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SERN
STATES...

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN
ROCKIES...

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OZARK
REGION...

..SRN MO/SE KS/NE OK/FAR NRN AR...
SEVERAL LINES OF THUNDERSTORMS ARE ONGOING ALONG THE ERN EDGE OF AN
UPPER-LOW EVIDENT ON WATER VAPOR IMAGERY ACROSS THE SRN PLAINS AND
OZARK REGION. REGIONAL PROFILES ACROSS SW MO SHOW GRADUALLY VEERING
WIND PROFILES WITH MODERATE VERTICAL SHEAR WHICH SHOULD BE FAVORABLE
FOR ROTATING STORMS. IN ADDITION...A WELL-DEFINED LOW-LEVEL JET IS
LOCATED ACROSS ERN OK WITH THE EXIT REGION OF THIS FEATURE LOCATED
ACROSS SE KS AND SW MO. THIS IS CREATING LOW-LEVEL SHEAR PROFILES
ACROSS THE REGION WHICH SHOULD BE FAVORABLE FOR A FEW TORNADOES WITH
THE STRONGER ROTATING STORMS LATE THIS AFTERNOON.

..NRN ROCKIES...
LATEST WATER VAPOR IMAGERY SHOWS A SWLY FLOW PATTERN IN PLACE ACROSS
THE NRN ROCKIES. AT THE SFC...A LOW IS PRESENT IN FAR NW SD WITH A
COLD FRONT LOCATED ACROSS FAR NRN WY EXTENDING NWWD TO NEAR BOZEMAN
MT. SFC DEWPOINTS ALONG THE BOUNDARY ARE MOSTLY IN THE LOWER TO MID
50S F AND DESTABILIZATION HAS TAKEN PLACE ALONG THE MOIST AXIS THIS
AFTERNOON WITH SBCAPE VALUES IN THE 1000 TO 1200 J/KG RANGE.
INSTABILITY WILL CONTINUE TO INCREASE AND CONVECTIVE INITIATION WILL
BE LIKELY IN THE HIGHER TERRAIN OF SW MT LATE THIS AFTERNOON. MODEL
FORECASTS ARE CONSISTENT WITH DEVELOPING A CLUSTER OF THUNDERSTORMS
MOVING THE ACTIVITY NEWD ACROSS THE SLIGHT RISK AREA THROUGH EARLY
EVENING.

CONCERNING THE SEVERE POTENTIAL...FORECAST SOUNDINGS ACROSS SW MT
LATE THIS AFTERNOON SHOW STRONG VERTICAL SHEAR PROFILES IN PLACE DUE
TO 30 TO 50 KT OF SWLY FLOW IN THE MID-LEVELS. IN ADDITION...THE
LATEST OBJECTIVE ANALYSIS SHOWS 850 TO 500 MB LAPSE RATES EXCEEDING
8.5 C/KM ACROSS MUCH OF SW MT. THIS ALONG WITH THE VERTICAL SHEAR
SHOULD BE SUFFICIENT FOR ROTATING STORMS WITH A POTENTIAL FOR LARGE
HAIL. THE SEVERE THREAT COULD CONTINUE THROUGH EARLY EVENING AS THE
STORMS MOVE NEWD INTO THE LOWER ELEVATIONS ALONG THE I-90 CORRIDOR.

..SERN STATES...
A WEAK FLOW PATTERN IS PRESENTLY IN PLACE ACROSS THE SRN U.S. WITH A
DIFFUSE FRONTAL BOUNDARY LOCATED ACROSS NRN MS...CNTRL AL AND NRN
GA. SFC DEWPOINTS AROUND 70 F AND WARMING TEMPS ARE RESULTING IN
MODERATE INSTABILITY ACROSS MOST OF THE SERN U.S. IN ADDITION...19Z
OBJECTIVE ANALYSIS SHOWS AN AXIS OF VERY STEEP LOW-LEVEL LAPSE RATES
EXCEEDING 8.5 C/KM FROM WRN SC EXTENDING SWWD ACROSS CNTRL GA INTO
AL AND ERN MS. PULSE THUNDERSTORMS THAT DEVELOP ALONG THIS CORRIDOR
IN THE HIGH INSTABILITY ENVIRONMENT MAY HAVE A POTENTIAL FOR WIND
DAMAGE. THE GREATEST SEVERE THREAT SHOULD BE CONCENTRATED AROUND
PEAK HEATING LATE THIS AFTERNOON.

..NRN PLAINS...
AN UPPER-LEVEL RIDGE IS CURRENTLY IN PLACE ACROSS THE NRN PLAINS
WITH A SFC LOW IN NWRN SD AND A WARM FRONT EXTENDING ENEWD ACROSS
SRN ND. CONVECTION SHOULD CONTINUE TO DEVELOP ACROSS NWRN ND THIS
AFTERNOON IN RESPONSE TO A SUBTLE SHORTWAVE TROUGH MOVING NEWD OVER
THE UPPER-LEVEL RIDGE. THE LATEST FORECAST SOUNDINGS ACROSS THE
REGION SHOW MODERATE VERTICAL SHEAR PRESENT AND THIS SHOULD BE
SUFFICIENT FOR ISOLATED SEVERE STORMS ESPECIALLY AS INSTABILITY
INCREASES LATE THIS AFTERNOON. HOWEVER...WARM MID-LEVEL TEMPS AND
CAPPING MAY DISCOURAGE THUNDERSTORM DEVELOPMENT AND THIS SHOULD KEEP
THE SEVERE THREAT MARGINAL ACROSS MOST OF ND THROUGH EARLY EVENING.

.BROYLES.. 06/30/2007

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