Severe Thunderstorm Warning 151, NWS Pueblo, CO

SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
230 PM MDT SAT OCT 11 1997

MULTITUDE OF FORECAST PROBLEMS TO CONTEND WITH TONIGHT AS A
STRONG UPPER TROUGH MOVES INTO THE ROCKIES...WITH WINDY
CONDITIONS AND UNSTABLE AIR AHEAD OF IT AND LARGE SCALE ASCENT
AND COOLER AIR MOVING IN WITH THE TROUGH.

AN AREA OF CSI INDUCED PRECIPITATION DEVELOPED OVER THE EASTERN
SAN JUAN MOUNTAINS THIS MORNING...AND THIS AREA HAS WEAKENED AND
SHIFTED EAST.  THIS AREA MAY HOLD TOGETHER THIS EVENING ON THE
ANTICYCLONIC SHEAR OF THE APPROACHING JET...MOVING OUT ONTO THE
PLAINS.  THE AIRMASS IS RELATIVELY DRY...BUT CSI MAY TAKE OFF
WHEN IT MOVES INTO MOISTER AIR FARTHER EAST ON THE PLAINS.

THE IMMEDIATE CONCERNS FOR LATE THIS AFTERNOON AND EVENING ARE
FOR ISALLOBARIC WINDS ON PORTIONS OF THE PLAINS AND THE POTENTIAL
FOR SEVERE WEATHER.  A DEVELOPING SURFACE LOW OVER NORTHERN
COLORADO IS INTENSIFYING WINDS ON THE PLAINS THIS AFTERNOON
...WITH SOME AREAS MEETING HIGH WIND CRITERIA.  THIS LOW SHOULD
LIFT OFF TO THE NORTHEAST BY EARLY THIS EVENING...ALLOWING A
REDUCTION IN THE WIND SPEEDS ON THE PLAINS.  CONCERNING SEVERE
POTENTIAL ON THE PLAINS...IT WILL TAKE SOME SORT OF TRIGGER TO
RELEASE THE INSTABILITY AND ITS HARD TO FIND ANYTHING AT THE
MOMENT.  STILL...IF THE STORMS DO GO...THEY WILL HAVE PLENTY OF
INSTABILITY...NOT TO MENTION THE HELICITY AVAILABLE TO PRODUCE
SUPERCELLS.

IT LOOKS LIKE SNOW SHOULD START IN THE EASTERN SAN JUAN MOUNTAINS
BY MIDNIGHT TONIGHT...THEN SPREAD EAST INTO THE SAN LUIS VALLEY
AND THEN THE SANGRE DE CRISTOS BY LATE TONIGHT.  THE SNOW MODEL
DOES NOT SUPPORT ANYTHING PAST ADVISORY CRITERIA.  THE PIKES PEAK
REGION AND WET MOUNTAINS WILL HAVE TO WAIT UNTIL THE SECOND
PERIOD FOR ANY SIGNIFICANT SNOWFALL.

FWC GUIDANCE FOR TONIGHT LOOKS GENERALLY REASONABLE.  POPS SEEM A
LITTLE HIGH AT COS AND PUB...WITH MAINLY A THREAT OF CONVECTIVE
PRECIPITATION.  ALSO...THE MIN AT COS LOOKS TOO LOW GIVEN THAT
THE FRONT SHOULDN'T COME THROUGH UNTIL AFTER THE FIRST PERIOD.

HAYNES