Tornado and Hail in Colorado, June 21, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
311 PM MDT WED JUN 21 2006

.DISCUSSION...MAIN FORECAST PROBLEM WILL CONTINUE TO BE CHANCE OF
PRECIPITATION THROUGH THE PERIOD. SECONDARY PROBLEM WILL BE HIGH
TEMPERATURES...ESPECIALLY TOMORROW. SATELLITE CONTINUING TO SHOW AN
ACTIVE AND PROGRESSIVE FLOW FROM THE CENTRAL PACIFIC INTO THE WESTERN
ATLANTIC. MEAN UPPER TROUGH STILL TO OUR WEST. SEVERAL SHORTWAVES
EMBEDDED IN THIS FLOW. ONE...WHICH COULD BE LEFT OVER CIRCULATION
FROM LAST NIGHT...IS OVER SOUTHEAST COLORADO WITH AN EXTENSION OF THE
TROUGH TO THE NORTH. THERE IS ANOTHER NEAR THE FOUR CORNERS AREA. THE
STRONGEST ONE LOOKS TO BE APPROACHING FROM THE NORTHWEST PORTION OF
THE COUNTRY. MAIN FRONT LOOKS TO HAVE PUSHED FURTHER SOUTH WITH LOW
LEVEL UPSLOPE IN PLACE OVER THE FORECAST AREA.

AT JET LEVEL...MODELS INITIALIZED FINE. AT MID LEVELS...BASED ON
SATELLITE MODELS HAVE CAPTURED THE SHORTWAVE TROUGH DETAILS WELL.
BASED ON UPPER AIR ANALYSIS...THE MODELS ARE ALSO CLOSE WITH THE GFS
DOING SLIGHTLY BETTER THAN THE OTHER MODELS. IT ESPECIALLY IS DOING
WELL WITH THE SHORTWAVES IN QUESTION. MODELS TENDED TO BE A LITTLE
DRY WITH THE GFS CLOSER. AT LOW LEVELS...THE UKMET DID BEST ON THE
TEMPERATURES FOLLOWED BY THE GFS. MODELS WERE CLOSE ON THE WIND
FIELD WITH THE GFS/WRF-NAM ABOUT THE SAME. WILL BE GOING WITH A
BLEND OF THE MODELS.

TONIGHT...RIGHT REAR QUADRANT OF NORTHERN JET STAYS OVER THE
FORECAST AREA...ESPECIALLY NORTHERN SECTIONS...THROUGH THE ENTIRE
NIGHT. CONVECTION HAS STARTED FROM THE WEST BUT STORM MOTIONS ARE
SLOW. AN OUTFLOW FROM CONVECTION OVER NEBRASKA HAS PUSHED INTO THE
NORTHEAST PORTION OF THE FORECAST AREA. MODELS CONTINUE TO INDICATE
THAT THE ENTIRE FORECAST AREA WILL GET SOMETHING WITH THE SOUTHERN
HALF SEEING THE MOST. WILL LAY OUT THE POPS THAT WAY.

THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT STAYS OVER THE EASTERN
PORTION OF THE FORECAST AREA IN THE MORNING. ALL MODELS SHOWING
ONGOING AND ACTUALLY EXPANDING PRECIPITATION DURING THE DAY...
ESPECIALLY IN THE MORNING. JUST GOING BY THE RUC13 WOULD SAY THERE IS
MORE PRECIPITATION COVERAGE ON THIS DAY THAN TONIGHT. MID AND UPPER
LEVEL LIFT...PROBABLY FROM NORTHERN GREAT BASIN SYSTEM...WOULD
SUPPORT THIS AS WELL. THEN THERE MAY BE SOME REDEVELOPMENT IN THE
WEST IN THE AFTERNOON. SO SLIGHT CHANCE TO CHANCE WILL BE MENTIONED
ALL DAY. WITH CLOUDS...PRECIPITATION...AND UPSLOPE WINDS...WILL TEND
TOWARD THE COOLER GUIDANCE.

RIGHT REAR QUADRANT OF THE JET AFFECTS THE SOUTHEAST HALF OF THE
FORECASET AREA DURING THE NIGHT. CURRENT PRECIPITATION FORECAST FOR
THE NIGHT IS MATCHING NEW GUIDANCE VERY WELL...AND DO NOT PLAN ON
CHANGING AT ALL.

FRIDAY/FRIDAY NIGHT...WEAK MID AND UPPER LEVEL LIFT COMES IN DURING
THE AFTERNOON AND THEN MOVES INTO THE WESTERN HALF OF THE FORECAST
AREA. MOISTURE APPEARS TO BE ADEQUATE. WILL HAVE SLIGHT CHANCE IN THE
COLORADO COUNTIES IN THE AFTERNOON. THEN WILL HAVE A SLIGHT CHANCE...
AT LEAST THROUGH THE CENTRAL PORTION OF THE FORECAST AREA THROUGH THE
NIGHT. WILL HAVE SOME SUN...AND WILL WARM IT UP A LITTLE ALTHOUGH NOT
MUCH WITH UPSLOPE WINDS AND MOIST GROUND.

SATURDAY...BOUNDARY MOVES INTO THE NORTHWEST HALF OF THE FORECAST
AREA DURING THE AFTERNOON AND THEN THROUGH THE AREA DURING THE
NIGHT. INTERESTINGLY ENOUGH...ALL THE MODELS INDICATE LIFT THROUGH
THE MID LEVELS INCREASING...BEGINNING RIGHT AT 12Z...THROUGH THE
DAY. IT GIVES ME SOME CONFIDENCE THAT ALL THE MODELS ARE INDICATING
THIS BUT ALL NOT PRODUCING PRECIPITATION EXCEPT FOR THE WRF-NAM.
WILL PUT SOME LOW CHANCE OF PRECIPITATION OF PRECIPITATION...AND
PROBABLY FOR THE DAY. WILL GO NEAR TO SLIGHTLY BELOW GUIDANCE FOR
MAXES.

FOR SUNDAY THROUGH WEDNESDAY...MODELS REMAIN CONSISTENT AND IN GOOD
AGREEMENT BETWEEN EACH OTHER AND PREVIOUS RUNS. SOME DIFFERENCES SHOW
UP TOWARD THE END OF PERIOD. HOWEVER...ESSENTIALLY WESTERN RIDGE WILL
BUILD AND LEAVE AREA OPEN TO SHORTWAVE TROUGHS MOVING THROUGH IN
NORTHWEST FLOW ALOFT. EAST TO SOUTH WINDS WILL KEEP LOW LEVEL
MOISTURE IN THE AREA. ALSO BOUNDARIES WILL BE IN AND NEAR THE
FORECAST AREA THROUGH THE PERIOD. KEPT SLIGHT CHANCE TO CHANCE POPS
IN THROUGH THE ENTIRE TIME. RIGHT NOW THE BEST CHANCE LOOKS TO BE
SUNDAY. IT GETS A LITTLE MORE IFFY IN THE MONDAY TO WEDNESDAY TIME
FRAME BUT AM LEARY OF THIS FLOW PATTERN. DURING THAT TIME...IT LOOKS
LIKE THE WESTERN PORTION WILL HAVE THE BEST CHANCE. WENT PRETTY CLOSE
TO GUIDANCE EXCEPT FOR THE END WHERE THE GFS LOOKS TOO COOL BECAUSE
OF CONVECTIVE FEEDBACK.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

BULLER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GOODLAND KS
1048 AM MDT WED JUN 21 2006

COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-221300-
YUMA-KIT CARSON-CHEYENNE CO-CHEYENNE KS-RAWLINS-DECATUR-NORTON-
SHERMAN-THOMAS-SHERIDAN-GRAHAM-WALLACE-LOGAN-GOVE-GREELEY-WICHITA-
DUNDY-HITCHCOCK-RED WILLOW-
1148 AM CDT WED JUN 21 2006 /1048 AM MDT WED JUN 21 2006/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EXTREME SOUTHWEST
NEBRASKA...NORTHWEST KANSAS AND EAST CENTRAL COLORADO.

.DAY ONE...TODAY AND TONIGHT

ANOTHER UPPER LEVEL DISTURBANCE WILL APPROACH THE TRI-STATE REGION
THIS AFTERNOON WHILE A FRONTAL BOUNDARY SLOWLY DRIFTS SOUTHEASTWARD
INTO NORTHWESTERN KANSAS. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED
TO DEVELOP IN EASTERN COLORADO AHEAD OF THIS DISTURBANCE WHILE OTHER
ISOLATED STORMS INITIATE ALONG THE FRONTAL BOUNDARY IN NORTHWEST
KANSAS. SOME OF THESE STORMS WILL BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS.

DURING THE LATE EVENING AND OVERNIGHT HOURS...THE STORMS WILL
ORGANIZE INTO A LARGE CLUSTER...SPREADING EAST AND SOUTHEAST ACROSS
PARTS OF NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. LARGE
HAIL...DAMAGING WINDS AND LOCALLY HEAVY RAIN ARE EXPECTED. THE
HIGHEST THREAT FOR SEVERE STORMS WILL BE SOUTH OF A LINE EXTENDING
FROM YUMA COLORADO TO COLBY AND HILL CITY KANSAS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

FOR THURSDAY THROUGH MONDAY THE WEATHER PATTERN CONTINUES TO
ADVERTISE LATE AFTERNOON AND EVENING THUNDERSTORMS DEVELOPING
ACROSS THE TRI-STATE AREA. SEVERE THUNDERSTORMS ARE POSSIBLE JUST
ABOUT EVERY DAY. DRIER WEATHER IS EXPECTED FOR TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED AFTER 3 PM MDT (4 PM CDT).

DDT/BTS