Hail and Damaging Winds in Colorado, June 20, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
231 PM MDT TUE JUN 20 2006

.DISCUSSION...MAIN FORECAST PROBLEM WILL BE CHANCE OF PRECIPITATION
THROUGH THE PERIOD. SATELLITE SHOWING A PROGRESSIVE PATTERN FOR THE
MOST PART. SOME AMPLIFICATION TAKING PLACE OVER THE CENTRAL AND
EASTERN PACIFIC. UPPER RIDGE HAS BEEN FLATTENED SOME AND PUSHED TO
THE EAST BY WOUND UP SYSTEM OVER SOUTHERN CANADA. MEAN TROUGH
POSITION IS STILL TO THE WEST WITH NUMEROUS SHORTWAVE TROUGHS
EMBEDDED WITHIN THIS FEATURE/FLOW. FAIRLY COLD AIR ALOFT WITH THIS
UPPER TROUGH. PREFRONTAL TROUGH IS THROUGH THE AREA WITH COLD FRONT
MOVING IN BEHIND IT PRETTY QUICKLY.

AT JET LEVEL...MODELS INITIALIZED WELL. AT MID LEVELS...MODELS
INITIALIZED SIMILARLY AND RATHER WELL. ECMWF DID A LITTLE BETTER ON
THE HEIGHT FIELD THAN THE GFS/UKMET. OVERALL THEY THOSE THREE ARE NOT
FAR APART BUT WOULD HAVE TO GIVE A SLIGHT ADVANTAGE TO THE ECMWF DUE
A BETTER HANDLE ON THE SOUTHERN RIDGE. AT LOW LEVELS...NAM LOOKED TO
BE DOING THE BEST ON THE WIND FIELD. WILL BE GOING WITH A BLEND OF
THE MODELS FOR THIS PACKAGE.

TONIGHT...WHERE DOES THE FRONT END UP AND HOW MUCH MOISTURE
AVAILABLILITY/AMOUNT OF UPSLOPE ARE THE BIG QUESTIONS FOR TONIGHT.
RIGHT ENTRANCE REGION OF JET IS CAUSING THUNDERSTORM DEVELOPMENT TO
THE NORTHWEST OF THE AREA. SHEARED OUT SHORTWAVE TROUGH JUST TO THE
WEST OF US WITH DEFINITE SMALL SCALE SPIN APPROACHING FROM SOUTH
CENTRAL COLORADO. RUC/GFS/UKMET WERE CATCHING THIS FEATURE THE BEST.
BOTH OF THESE FEATURES AFFECT THE NORTHERN TWO TIERS OF COUNTIES
THE MOST AND MAY BRUSH THE SOUTHEAST THREE COUNTIES. THE 700 MB
TEMPERATURES ARE ALSO THE LOWEST IN THE NORTHERN COUNTIES. ALSO THE
FRONT MAY AFFECT THE SOUTHEAST THREE COUNTIES. MOISTURE LEVELS ARE
ALSO THE BEST IN THESE AREAS. SO WILL HAVE THE HIGHEST POPS IN THESE
LOCATIONS.

WEDNESDAY/WEDNESDAY NIGHT...SHORTWAVE TROUGH MOVES IN FROM THE WEST
LATE IN THE AFTERNOON AND THEN ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA DURING THE NIGHT. HOWEVER...RIGHT REAR QUADRANT OF
JET IS CLOSER TO THE NORTHERN PORTION OF THE FORECAST AREA DURING THE
NIGHT. PLAN ON KEEPING HIGH POPS WITH THE HIGHEST IN THE SOUTHERN
PORTION. PLAN ON GOING NEAR TO SLIGHTLY ABOVE GUIDANCE.

THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT AND SHORTWAVE TROUGH
IN NORTHWEST FLOW ALOFT MOVE THROUGH DURING THE LATE AFTERNOON AND
NIGHT. STORMS COULD GO WELL INTO THE NIGHT. WILL HAVE HIGH CHANCE
POPS AT LEAST FOR THE NIGHT PERIOD. PLAN ON NEAR GUIDANCE.

FRIDAY...THUNDERSTORMS LOOK TO HOLD OFF TIL LATE...ESPECIALLY IF WE
HAVE A BIG EVENT. WILL PROBABLY HAVE SOME CHANCE IN OUR COLORADO
COUNTIES FOR THE AFTERNOON. WILL GO NEAR GUIDANCE.

FOR SATURDAY THROUGH TUESDAY...MODELS NOT TOO DIFFERENT FOR MOST OF
THE PART...AND ARE CONSISTENT WITH PREVIOUS RUNS. ONE TREND WAS THE
WESTERN UPPER RIDGE AND EASTERN PACIFIC TROUGH TO BE A LITTLE MORE
AMPLIFIED AND A LITTLE FURTHER WEST THAN THE PREVIOUS RUN. THIS IS
REASONABLE BASED ON CURRENT DATA. HOWEVER...MODELS START DIVERGING
AND CHANGING ON DAYS 6 AND 7. THE MODELS WANT TO BRING UPPER TROUGH
FURTHER EAST. AGREE WITH NCEPS ASSESSMENT OF KEEPING LOWER HEIGHTS
OFF THE COAST. LIKE A MORE AMPLIFIED RIDGE AND FURTHER WEST POSITION.
BELIEVE THE GFS DOES BETTER WITH THIS SCENARIO UNTIL DAY 6 THEN THE
ECMWF STARTS DOING BETTER. MODELS ARE A LITTLE DRIER THAN
YESTERDAY. HOWEVER...AM LEARY OF NORTHWEST FLOW ALOFT AND EMBEDDED
SHORTWAVES THAT MODELS WILL HAVE DIFFICULTY SEEING. RIGHT NOW WILL
KEEP SLIGHT CHANCE TO LOW CHANCE POPS THROUGH MOST OF THE PERIOD.
TUESDAY DOES LOOK DRY...AND WILL HAVE IT THAT WAY RIGHT NOW. WILL
NOT STRAY TOO FAR FROM GUIDANCE EXCEPT WHEN GFS IS SUFFERING FROM
CONVECTIVE FEEDBACK.

&&

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

BULLER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GOODLAND KS
1046 AM MDT TUE JUN 20 2006

COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-211230-
YUMA-KIT CARSON-CHEYENNE CO-CHEYENNE KS-RAWLINS-DECATUR-NORTON-
SHERMAN-THOMAS-SHERIDAN-GRAHAM-WALLACE-LOGAN-GOVE-GREELEY-WICHITA-
DUNDY-HITCHCOCK-RED WILLOW-
1146 AM CDT TUE JUN 20 2006 /1046 AM MDT TUE JUN 20 2006/

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

AN UPPER LEVEL DISTURBANCE APPROACHING THE AREA FROM THE WEST WILL
AID IN THE FORMATION OF ISOLATED THUNDERSTORMS OVER COLORADO THIS
AFTERNOON. BY VERY LATE THIS AFTERNOON THESE STORMS WILL MOVE
EASTWARD...REACHING LOCATIONS ALONG AND WEST OF A LEOTI KANSAS TO
BURLINGTON AND WRAY COLORADO LINE. SOME OF THESE STORMS COULD
BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY
THREATS. THESE STORMS WILL SPREAD EASTWARD INTO PORTIONS OF NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA DURING THE EVENING AND OVERNIGHT
HOURS. THESE STORMS WILL ORGANIZE INTO A CLUSTER MOVING NORTHEAST
ACROSS AREAS MAINLY NORTH OF INTERSTATE 70. LARGE HAIL...DAMAGING
WINDS AND POSSIBLY SOME LOCALLY HEAVY RAIN WILL OCCUR THROUGH
MIDNIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A MUCH STRONGER DISTURBANCE WILL MOVE INTO THE AREA FROM EASTERN
COLORADO DURING THE MID TO LATE AFTERNOON HOURS WEDNESDAY. SEVERE
THUNDERSTORMS ARE EXPECTED ACROSS PARTS OF THE TRI STATE AREA WITH
LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREAT. DURING THE LATE
EVENING AND OVERNIGHT HOURS THE PRIMARY THREAT WILL BE HAIL LESS
THEN AN INCH IN DIAMETER...GUSTY WINDS TO 50 MPH AND LOCALLY HEAVY
RAIN AS THE STORMS ORGANIZE INTO A LARGE CLUSTER.

FOR THURSDAY THROUGH MONDAY THE WEATHER PATTERN CONTINUES TO
ADVERTISE LATE AFTERNOON AND EVENING THUNDERSTORMS MOVING OUT OF
EASTERN COLORADO INTO WESTERN KANSAS AND NEBRASKA DURING THE
EVENING AND OVERNIGHT HOURS. SEVERE THUNDERSTORMS ARE POSSIBLE
JUST ABOUT EVERY DAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED AFTER 4 PM MDT (5 PM CDT).

LAMMERS