Hail in Colorado, June 17, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
350 AM MDT TUE JUN 17 2008

.SHORT TERM...PROBLEM OF THE DAY APPEARS TO BE THE IMPACT OF
SHORTWAVE TIMING ON CONVECTION. MODELS ARE IN DECENT AGREEMENT ON
THE WEAK TROUGH MOVING EAST OF COLORADO EARLY THIS MORNING WITH
HEIGHTS REBUILDING BEHIND IT THIS AFTERNOON. A SOUTHWESTERLY JET
STREAK SPREADS FROM NEVADA INTO WYOMING THIS AFTERNOON. THIS PUTS
OUR AREA IN WEAK SUBSIDENCE DURING THE AFTERNOON AND EVENING. AT LOW
LEVELS SOUTH WINDS WILL PERSIST ON THE PLAINS...THOUGH THE DIURNAL
ACCELERATION MAY BE MESSED UP BY THE SHORTWAVE TIMING. THIS MAY WIND
UP DEPENDING ON HOW CLOSE THE PRESSURE FALLS IN WYOMING ARE THIS
AFTERNOON. WITH WESTERLY FLOW OFF THE GROUND...DRIER AIR WILL MOVE
OVER THE PLAINS AND MIX TO THE SURFACE OVER AT LEAST THE WESTERN
PART OF THE PLAINS. NEAR THE EASTERN BORDER THERE WILL BE STRATUS
THIS MORNING AND A CAPPING INVERSION THAT MAY HOLD ALL DAY...IF IT
DOES BREAK DRIER AIR WILL BE MIXING DOWN. SO IT APPEARS WE HAVE A
DECENT CHANCE OF DRY CONVECTION WEST OF ABOUT FORT MORGAN...WITH A
BETTER CHANCE OF RAIN FURTHER EAST BUT MAINLY THIS EVENING. NOT SO
SURE THE MOISTURE CONVERGENCE WILL SUSTAIN CONVECTION IN THE EVENING
EITHER AS LOW LEVEL WINDS DO NOT LOOK TOO STRONG. STILL A SMALL
SEVERE THREAT BUT FIGURE A LITTLE MIXING WOULD KEEP CAPES BELOW 1000
J/KG...HIGHER EAST OF OUR AREA IF IT IS REALIZED. NAM IS SHOWING A
SERIOUS MCS DROPPING SOUTH INTO WESTERN KANSAS JUST CLIPPING THE
EASTERN BORDER OVERNIGHT...WHILE THE GFS HAS NOTHING SUBSTANTIAL...
LEANING TOWARD THE GFS GIVEN THE ENVIRONMENT. DROPPED POPS AND CLOUD
COVER SLIGHTLY ON THE PLAINS THIS AFTERNOON...OTHERWISE NO
SIGNIFICANT CHANGES.

.LONG TERM...THE UPPER RIDGE AXIS IS PROGGED TO REMAIN JUST WEST OF
THE FORECAST AREA THROUGH THURSDAY NIGHT WITH WEST-NORTHWESTERLY
FLOW ALOFT.  AGAIN...THERE IS LITTLE BUT BENIGN SYNOPTIC SCALE
ENERGY PROGGED FOR THE FORECAST AREA THROUGH THE PERIODS.  THE
BOUNDARY LAYER FLOW WILL BE RELATIVELY WEAK THROUGH THURSDAY NIGHT.
THE GFS HAS A BIT OF A SURGE AND WEAK UPSLOPE FOR THE PLAINS EITHER
LATE WEDNESDAY NIGHT ON INTO THURSDAY DEPENDING ON THE MODEL.  FOR
MOISTURE...THERE IS SOME ON WEDNESDAY...A BIT MORE FOR THURSDAY.
THE NAM HAS QUITE A BIT IN THE LOWER LEVELS FOR THE PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING.  THE GFS HAS THIS MORE ON THURSDAY MORNING
BUT TO A LESSER DEGREE.  THE DEW POINT FIELDS SHOW THE HIGHEST
BOUNDARY LAYER VALUES ON THURSDAY FOR THE PLAINS AND FOOTHILLS.  ON
WEDNESDAY THE WESTERN PLAINS ARE IN THE 30S F WITH 50S PLUS
RELEGATED TO THE FAR NORTHEAST CORNER.  THE BEST THETA-E AXIS IS
JUST EAST OF THE FORECAST AREA LATE DAY WEDNESDAY.  ON THURSDAY...IT
IS LOCATED OVER MUCH OF EASTERN COLORADO.  CROSS SECTIONS HAVE STEEP
LAPSE RATES OVER THE FORECAST AREA LATE DAY WEDNESDAY.  LATE DAY
THURSDAY SHOWS SOME CAPPING OVER THE EASTERN THIRD OF THE FORECAST
AREA LATE IN THE DAY.  THE CAPE IS PRETTY HIGH LATE DAY WEDNESDAY
OVER THE FOOTHILLS AND EASTERN PLAINS.  FOR THURSDAY...THE BEST
VALUES ARE OVER THE FOOTHILLS AND PALMER RIDGE.  SO FOR POPS...
THURSDAYS MOISTURE LOOKS BETTER THAN WEDNESDAYS...BUT WEDNESDAYS
INSTABILITY IS BETTER THAN THURSDAYS.  WILL NOT ALTER MUCH.  WILL
MAINLY KEEP 10%-20%S EVERYWHERE.  FOR TEMPERATURES...WEDNESDAY HIGHS
ARE 1-3 C WARMER THAN TODAYS.  THURSDAYS READINGS COOL OFF SOME
2.0-3.5 C FROM WEDNESDAYS.  FOR THE LATER DAYS...FRIDAY THROUGH
MONDAY...MODELS KEEP THE UPPER RIDGE AT HAND THROUGH THE PERIOD.
THEY NOW SHOW THE RIDGE AXIS GETTING EAST OF THE FORECAST AREA
SUNDAY INTO MONDAY.  THIS FEATURE HAS BEEN MOVING ABOUT OVER THE
PAST FEW RUNS.  BASICALLY...THERE IS LITTLE TO CHANGE.

&&

.AVIATION...ISOLATED HIGH BASED THUNDERSTORMS ARE EXPECTED BETWEEN
22Z AND 03Z. LIGHTNING AND BRIEF GUSTY WINDS TO AROUND 30 KNOTS ARE
THE MAIN THREAT FROM THE STORMS...BUT THE PROBABILITY OF OCCURRENCE
AT A POINT IS LESS THAN 20 PERCENT.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...NONE.

&&

GIMMESTAD/RJK

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE DENVER CO
1136 AM MDT TUE JUN 17 2008

COZ030>051-181200-
JACKSON COUNTY BELOW 9000 FEET-WEST JACKSON AND WEST GRAND
COUNTIES ABOVE 9000 FEET-GRAND AND SUMMIT COUNTIES BELOW 9000
FEET-SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-SOUTH AND SOUTHEAST
GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/GILPIN/CLEAR CREEK/
SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE 9000 FEET-LARIMER AND
BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET-JEFFERSON AND WEST
DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR CREEK/NORTHEAST PARK
COUNTIES BELOW 9000 FEET-CENTRAL AND SOUTHEAST PARK COUNTY-LARIMER
COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON
COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY-NORTH DOUGLAS
COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE COUNTIES/
EAST BROOMFIELD COUNTY-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES
ABOVE 6000 FEET-NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD
COUNTY-MORGAN COUNTY-CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES-
NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN
COUNTY-SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN
COUNTY-LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS
COUNTY-
1136 AM MDT TUE JUN 17 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON THE PLAINS OF
NORTHEAST COLORADO TODAY...GENERALLY EAST OF A LINE CONNECTING
GROVER...FORT MORGAN...DEER TRAIL AND ELBERT. LOW LEVEL...
INCREASINGLY MOIST SOUTHEAST UPSLOPE FLOW...COUPLED WITH STRONG
DAYTIME HEATING...WILL PRODUCE FAVORABLE INSTABILITY AND DEEP LAYER
SHEAR TO PRODUCE ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WITHIN
THIS RISK AREA AFTER 2 PM TODAY. A FEW THUNDERSTORMS MAY THEN
BECOME SEVERE AFTER 4 PM ONCE MAXIMUM TEMPERATURES ARE REACHED. THE
MAIN THREAT WILL BE HAIL UP TO 1 1/2 INCH IN DIAMETER AND
THUNDERSTORM WIND GUSTS OF AT LEAST 60 MPH. THUNDERSTORMS MAY LINGER
ON THE PLAINS BEYOND MIDNIGHT...ALTHOUGH THE RISK FOR SEVERE WEATHER
SHOULD DIMINISH AFTER 10 PM THIS EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE WILL BE A SLIGHT CHANCE OF LATE DAY SHOWERS AND THUNDERSTORMS
FOR MUCH OF THE FORECAST AREA THROUGH NEXT MONDAY...WITH THE BEST
CHANCES OVER THE EASTERN PLAINS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION EAST OF THE I-25 URBAN CORRIDOR MAY BE NECESSARY
AFTER 2 PM TODAY.

BAKER/ENTREKIN