SPC AC 050557
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1257 AM CDT FRI JUN 05 2009
VALID 051200Z - 061200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL AND SOUTHERN
PLAINS...
...CENTRAL PLAINS/SRN HIGH PLAINS...
STUBBORN UPPER RIDGE WILL FINALLY BREAK DOWN OVER THE HIGH PLAINS
LATER FRIDAY AS SWRN U.S. SPEED MAX EJECTS ACROSS AZ INTO THE
4-CORNERS REGION. ALTHOUGH GREATEST HEIGHT FALLS WILL SPREAD ACROSS
THE GREAT BASIN AND INTERIOR WEST...NWLY H5 FLOW IN THE LEE OF THE
CNTRL ROCKIES WILL BACK TO THE WSW...ROUGHLY 250-260 DEG...BY
06/00Z. LEE CYCLOGENESIS WILL ALSO DEVELOP AT THE SFC OVER NERN CO
WHICH WILL MAINTAIN MOIST LOW LEVEL TRAJECTORIES DUE TO ELY
COMPONENT...PRIMARILY NORTH OF I-70. LATEST MODEL GUIDANCE
INDICATES STRONG HEATING WILL OCCUR SOUTH OF THE PALMER DIVIDE INTO
WRN KS. THIS SHOULD PROVE INSTRUMENTAL IN AFTERNOON THUNDERSTORM
DEVELOPMENT AS TEMPERATURES SOAR TO NEAR 80F. CONVECTIVE
TEMPERATURES SHOULD BE BREACHED AND THUNDERSTORMS WILL DEVELOP OFF
THE HIGHER TERRAIN WITHIN UPSLOPE FLOW REGIME. FORECAST PROFILES
SUGGEST SUPERCELLS WILL EASILY DEVELOP WITHIN STRONGLY SHEARED
ENVIRONMENT CHARACTERIZED BY SBCAPE VALUES ON THE ORDER OF 1500
J/KG. IT APPEARS SCATTERED SUPERCELLS WILL EVOLVE BY MID-LATE
AFTERNOON THEN SPREAD/DEVELOP EWD INTO SWRN NEB WHERE LOW LEVEL
SHEAR WILL BE MAXIMIZED. LARGE HAIL SHOULD ACCOMPANY MOST STORMS
THROUGH EARLY EVENING...AND WHERE DEW POINTS CAN HOLD IN THE 50S
THERE APPEARS TO BE A REASONABLE THREAT FOR AT LEAST A FEW
TORNADOES. DURING THE OVERNIGHT HOURS...LLJ WILL STRENGTHEN OVER
THE CNTRL PLAINS. WAA WILL ENHANCE EWD MOVING COMPLEX OF STORMS AS
THEY MOVE ACROSS NEB DURING THE LATTER HALF OF THE PERIOD. LARGE
HAIL IS THE PRIMARY THREAT WITH ACTIVITY AFTER MIDNIGHT.
STRONG HEATING ALONG THE DRYLINE WILL ONCE AGAIN ASSIST ISOLATED
THUNDERSTORM DEVELOPMENT SWD INTO THE TX SOUTH PLAINS. BOUNDARY
LAYER AIRMASS IS GRADUALLY MOISTENING ACROSS THIS REGION AS SFC
ANTICYCLONE SHIFTS EAST ACROSS TX. ALTHOUGH SHEAR PROFILES WILL NOT
BE THAT STRONG IT APPEARS DEEP LAYER SHEAR WILL BE MORE THAN
ADEQUATE FOR A FEW ORGANIZED MULTI-CELL THUNDERSTORMS...OR PERHAPS
AN ISOLATED SLOW MOVING SUPERCELL. LARGE HAIL AND DAMAGING WINDS
ARE THE PRIMARY THREATS.
...WRN WY TO ERN ORE...
UPPER TROUGH WILL BECOME ORIENTED ALONG AN AXIS FROM SWRN MT TO
CNTRL CA BY EARLY EVENING...WHILE QUITE COLD MID LEVEL
TEMPERATURES...H5 TO -18C...SETTLE INTO THE GREAT BASIN BENEATH THIS
FEATURE. WITH STRONG MID LEVEL FLOW EJECTING ACROSS UT THIS WILL
ALLOW A RATHER PRONOUNCED DRY SLOT TO SURGE ACROSS THE GREAT BASIN
INTO UT. GREATER MOISTURE PLUME CHARACTERIZED BY PW VALUES ON THE
ORDER OF 0.75 IN WILL HOLD ACROSS MUCH OF WRN WY/ID INTO ERN
ORE...WELL REMOVED FROM STRONGER SWLY FLOW REGIME. SCATTERED
THUNDERSTORMS SHOULD EASILY DEVELOP WITHIN THIS MOIST
ENVIRONMENT...POSSIBLY INITIATING AS EARLY AS 18Z. ISOLATED LARGE
HAIL AND GUSTY WINDS ARE THE PRIMARY THREATS. AT THIS TIME IT
APPEARS AIRMASS OVER UT WILL DRY TOO QUICKLY AND REMAIN TOO STABLE
TO SUPPORT ANY MEANINGFUL THREAT FOR ORGANIZED SEVERE THUNDERSTORMS.
..DARROW/JEWELL.. 06/05/2009
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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