Hail and Damaging Winds in Colorado, August 31, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
500 PM MDT SAT AUG 31 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 150 PM MDT SAT AUG 31 2013

LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW WEAKENED H5 RIDGE
EXTENDING ACROSS THE SW HALF OF THE CWA WITH WEST TO NORTHWEST FLOW
BEGINNING TO SHIFT SOUTH INTO SOUTHERN WYOMING AND MOST OF NEBRASKA.
A STRONG SHORTWAVE TROUGH HAS KICKED A COLD FRONT SOUTH TO THE NE
PANHANDLE. AHEAD OF THIS FEATURE WEAK MID LEVEL FRONTOGENETICAL
FORCING COMBINED WITH AN EXITING SHORTWAVE TROUGH OVER EASTERN
NEBRASKA LED TO LIGHT SHOWER/ISOLATED THUNDERSTORM DEVELOPMENT THIS
MORNING. LATEST RADAR TRENDS SHOW THIS ACTIVITY LINGERING OVER THE
CWA...WITH ADDITIONAL ACTIVITY DEVELOPING UPSTREAM OVER THE HIGHER
TERRAIN IN CENTRAL COLORADO AHEAD OF A WEAKER SHORTWAVE TROUGH OVER
EASTERN WYOMING.

AS THE SHORTWAVE TROUGH OVER WYOMING DROPS SOUTH TONIGHT IT WILL
HELP PUSH THE COLD FRONT SOUTH INTO NW KANSAS...WITH LARGE SCALE
FORCING OVERSPREADING OUR CWA. EARLY AFTERNOON SHOWER/THUNDERSTORM
ACTIVITY SHOULD INCREASE IN COVERAGE THROUGH 00Z IN RESPONSE TO THE
INCREASE IN LARGE SCALE SUPPORT AND FURTHER DESTABILIZATION. PWATS
REMAIN VERY HIGH THROUGH SUNDAY MORNING (1.3-1.5) SO THERE IS PLENTY
OF MOISTURE TO WORK WITH DURING THIS EVENT. AS SHORTWAVE DROPS SOUTH
THERE SHOULD BE AN INCREASE IN COVERAGE BEFORE SUBSIDENCE QUICKLY
MOVES IN FROM THE NORTH AFTER MIDNIGHT. MODELS DO SHOW COLD POOL
LINGERING IMMEDIATELY BEHIND COLD FRONT OVER OUR SOUTHERN CWA
THROUGH SUNDAY MORNING. THIS COLD POOL MAY ACTUALLY LINGER INTO THE
AFTERNOON...WHICH COULD HELP LEAD TO DIURNAL SHOWER/THUNDERSTORM
DEVELOPMENT BEFORE 00Z IN OUR SOUTH...SO I KEPT THUNDERSTORM MENTION
FOR THESE LOCATIONS.  BASED ON LATEST HRRR/RUC...I AM STILL UNSURE
ABOUT WHERE BEST COVERAGE WILL DEVELOP...HOWEVER ONGOING 40 POPS
SEEMED REASONABLE RIGHT. INSTABILITY MAY BE MARGINAL ACROSS MUCH OF
OUR CWA THROUGH TONIGHT...SO WE ARE PROBABLY ONLY LOOKING AT AN
ISOLATED SEVERE THUNDERSTORM THREAT.  WITH VERY MOIST AIR MASS AND
SLOW STORM MOTIONS I COULDNT HEAVY RAINFALL WITH ANY THUNDERSTORM
ACTIVITY. HOWEVER...IM NOT SURE ABOUT HOW WIDESPREAD THAT THREAT
WILL REALLY BE. WE MAY JUST END UP WITH A GOOD THREAT OF LIGHT
RAIN...WITH A FEW ISOLATED POCKETS OF MODERATE-HEAVY RAINFALL.

REGARDING TEMPS...WITH CLEARING SKIES IN THE NORTH TEMPS HAVE
FINALLY BEGUN TO WARM ACROSS MUCH OF THE CWA...HOWEVER A DOWNWARD
ADJUSTMENT WAS NEEDED TO CATCH CURRENT TRENDS THIS AFTERNOON. AFTER
THE COLD FRONT PUSHES SOUTH TONIGHT A MUCH MORE SEASONABLE AIR MASS
WILL SETTLE OVER OUR CWA. HIGH ARE CURRENTLY PROGGED TO BE IN THE
MID-UPPER 80S SUNDAY...WHICH IS RIGHT ABOUT WHERE WE WOULD EXPECT TO
BE FOR LABOR DAY WEEKEND.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 204 PM MDT SAT AUG 31 2013

THE UPPER RIDGE IS IN PLACE AGAIN OVER THE ROCKIES AND HIGH PLAINS
FROM SUNDAY NIGHT THROUGH ALL OF NEXT WEEK. DIFFERENCES BEGIN TO
SHOW UP IN MODEL PROGRESSIONS OF THE UPPER LOW CENTER RIDING UP
OVER THE RIDGE IN THE PACIFIC NORTHWEST AND THE OVERALL FLATTENING
OF THE RIDGE IN THE FRIDAY NIGHT THROUGH SATURDAY TIME PERIOD.

SURFACE COOLER HIGH PRESSURE AREA STAYS MOSTLY OVER THE CENTRAL
PLAINS AND CENTRAL HIGH PLAINS SUNDAY NIGHT AND MONDAY BEFORE
PUSHING FURTHER EAST WITH A DEEPENING LEE TROUGH THAT PERSISTS IN
THE VICINITY OF THE EASTERN COLORADO BORDER. WITH SOUTHERLY FLOW
ACROSS THE FORECAST AREA...EXPECT MORE DRY AND WARM CONDITIONS
THROUGH THE UPCOMING WORK WEEK AND NEXT WEEKEND WITH HIGHS IN THE
90S AND LOWS IN THE 60S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 500 PM MDT SAT AUG 31 2013

FOR KGLD AND KMCK VFR CONDITIONS EXPECTED. AT 23Z FRONTAL
BOUNDARY LOCATED NEAR K2V5 AND KSYF WHERE SHOWERS AND
THUNDERSTORMS ONGOING. WIND GUSTS TO 35KTS REPORTED AT KSYF. FRONT
NOT EXPECTED TO PASS THROUGH TERMINALS TIL THE 03Z-07Z TIMEFRAME
WHERE NORTHEAST WINDS GUSTING AROUND 20KTS POSSIBLE. THIS WILL
CONTINUE THROUGH MUCH OF THE DAY SUNDAY BEFORE DECREASING TO
AROUND 10KTS OR LESS BY LATE IN THE AFTERNOON. CANT RULE OUT SOME
PRECIPITATION AT EITHER TERMINAL TIL THE FRONT PASSES WITH DRY
WEATHER EXPECTED BEHIND IT. DISTANCE SPEED TOOL SUGGESTS CURRENT
AREA OF THUNDERSTORMS AT TAF ISSUANCE WILL BE IN THE VICINITY OF
KGLD FOR A FEW HOURS SO HAVE ADDED A TEMPO GROUP FOR THUNDERSTORMS
THROUGH 02Z. CONFIDENCE NOT QUITE AS HIGH AT KMCK TO INCLUDE A
THUNDER/PRECIP GROUP BUT WILL WATCH CLOSELY AND ADD ONCE
CONFIDENCE INCREASES SHOULD THAT TERMINAL BE IMPACTED.

&&

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

SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...99

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE GOODLAND KS
1041 AM MDT SAT AUG 31 2013

COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-011415-
YUMA-KIT CARSON-CHEYENNE CO-CHEYENNE KS-RAWLINS-DECATUR-NORTON-
SHERMAN-THOMAS-SHERIDAN-GRAHAM-WALLACE-LOGAN-GOVE-GREELEY-WICHITA-
DUNDY-HITCHCOCK-RED WILLOW-
1041 AM MDT SAT AUG 31 2013 /1141 AM CDT SAT AUG 31 2013/

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE
AFTERNOON...WITH ACTIVITY INCREASING IN COVERAGE BY THIS EVENING
OVER EASTERN COLORADO AND SLOWLY MOVING EAST THROUGH THE
OVERNIGHT HOURS. ALTHOUGH WIDESPREAD SEVERE WEATHER IS NOT
EXPECTED...IT WILL BE POSSIBLE FOR A FEW OF THESE STORMS TO BECOME
SEVERE WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS. SOME
OF THESE THUNDERSTORMS WILL ALSO BE CAPABLE OF PRODUCING LOCALLY
HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

ON SUNDAY...ISOLATED TO SCATTERED THUNDERSTORMS MAY LINGER ACROSS
THE AREA UNTIL LATE IN THE AFTERNOON...GENERALLY SOUTH OF
INTERSTATE 70. THESE STORMS ARE NOT EXPECTED TO BECOME SEVERE BUT
WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GOODLAND KS
500 PM MDT SAT AUG 31 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     HAIL             7 SSE WRAY              39.99N 102.18W
08/31/2013  M0.75 INCH       YUMA               CO   TRAINED SPOTTER

&&

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