Funnel Cloud in Colorado, September 12, 2002

SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO COLORADO
255 PM MDT THU SEP 12 2002

CONVECTIVE CHANCES THROUGH FRI NIGHT THE CONCERN.

CURRENTLY: UPPER LOW SPINNING OVER UTAH WITH CONVECTION FIRING
ACROSS THE MOUNTAINS. SLIGHTLY COLDER TEMPS ALOFT AND BETTER
UPPER DIFLUENCE AIDING CONVECTION OVER THE NORTHERN AND WRN FRINGES
OF THE CWFA...WHILE POCKET OF SLIGHTLY WARMER AIR AT 500MB OVER SERN
CO SEEMS TO BE SUPPRESSING ACTIVITY.

TONIGHT...SCATTERED SHOWERS AND THUNDERSTORMS ONCE AGAIN...WITH
HIGHEST POPS OVER THE MOUNTAINS. WONT PUT ANY ENDING TIME IN THE
FORECAST AS AT LEAST ISOLATED ACTIVITY WILL PERSIST WITH UPPER LOW
NEARBY.

FRI-FRI NIGHT...UPPER LOW LIFTS OUT TO THE NORTH OF COLORADO THOUGH
TROUGH AXIS WILL REMAIN ACROSS THE STATE. WEAK EASTERLY FLOW
DEVELOPS ACROSS THE PLAINS AS SURFACE LOW SAGS INTO NERN NM BY LATE
AFTERNOON. SOME DRYING NOTED IN THE MID AND UPPER LEVELS...THOUGH
LOW LEVELS REMAIN MOIST. UPPER LEVEL TEMP PROGS SUGGEST LAPSE RATES
WILL BE STEEPER OVER THE EAST FRI AFTERNOON AS 500 TEMPS COOL.
CURRENT CHANCE POPS LOOK FINE FOR ALL AREAS. COOL SURFACE HIGH
BUILDS IN ACROSS CO OVERNIGHT WHICH SHOULD SLOWLY END PRECIP AS LOW
LEVELS STABILIZE AND FLOW BECOMES MORE NRLY DOWNSLOPE. ROUGHLY 10F
DIFFERENCE BETWEEN FWC AND MAV MAXES...LEANED TOWARD WARMER FWC
VALUES.

SAT...SURFACE HIGH CONTINUES TO BUILD ACROSS THE STATE WITH SLIGHT
INCREASE IN NRLY SFC WINDS AS GRADIENTS INCREASE. KEPT THE DRY
FORECAST GOING DESPITE SOME LIGHT QPF ON THE MODELS ALONG THE NM
BORDER. SUSPECT DRY AIR ALOFT AND FAIRLY STABLE SURFACE AIR WILL WIN
OUT...THOUGH GRADIENTS MIGHT BECOME ENOUGH EASTERLY TO PROMOTE SOME
SCATTERED CLOUDS ALONG THE ERN MTNS IN THE AFTERNOON. GUIDANCE TEMPS
A LITTLE CLOSER...THOUGH AGAIN SHADED TOWARD SLIGHTLY WARMER FWC.

SUNDAY...WARM-UP BEGINS AS UPPER RIDGE BUILDS OVER THE ROCKIES
WITH DEEP TROUGH OVER THE PACIFIC NW. WITH DRIER AIR IN PLACE...
MORNING LOWS COULD BE FAIRLY COOL...WITH A BIG DIURNAL SWING BY
AFTERNOON WITH WEAK DOWNSLOPE ALONG THE ERN MTNS. CURRENT GRIDS
LOOK GOOD.

MON-THU: FAIRLY TYPICAL LATE SUMMER/EARLY FALL WRLY UPPER FLOW
SHOULD BRING MILD AND DRY WX TO MOST OF THE AREA THROUGH THE WEEK.
SOME DIFFERENCE IN MODEL SOLUTIONS BY MID WEEK CONCERNING THE WRN
U.S. UPPER TROUGH...WITH UKMET DEEPEST...ECMWF MOST PROGRESSIVE...
AVN/GFS IN BETWEEN. COULD SEE SOME LIGHT PRECIP WEST OF THE CONT DVD
TUE/WED IF DEEPER SOLUTIONS VERIFY...THOUGH THIS LOOKS LIKE A LONG
SHOT AT BEST AND WILL KEEP FORECAST DRY FOR NOW. SOME CONCERN ABOUT
INCREASING WIND SPEEDS IN THE MTNS TUE/WED IF AVN VERIFIES...THOUGH
EUROPEAN SOLUTION ISNT QUITE AS STRONG. WONT ADD WINDY TO
EXTENDED PDS YET...THOUGH IT BEARS WATCHING.

.PUB...NONE.

PETERSEN