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000
FXUS65 KCYS 190448
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1048 PM MDT SAT MAY 18 2013

.UPDATE...
ISSUED AT 630 PM MDT SAT MAY 18 2013

LATEST RADAR IMAGERY SHOWING CONVECTION OUT IN THE PANHANDLE
WANING. IT HAS BEEN WORKED OVER PRETTY GOOD FROM EARLIER
CONVECTION AND NOW LOOKS MORE STRATIFORM THAN ANYTHING. WENT AHEAD
AND CANCELLED THE TORNADO WATCH OUT THERE AND HAVE UPDATED
PRODUCTS. STILL A CHANCE FOR THUNDERSTORMS...BUT THE RISK FOR
TORNADOES HAS BEEN SIGNIFICANTLY REDUCED.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1236 PM MDT SAT MAY 18 2013

18Z SURFACE ANALYSIS SHOWED SIGNIFICANT MOISTURE POOLING IN THE
NEBRASKA PANHANDLE WITH MOST LOCATIONS OBSERVING DEW POINTS IN THE
50S. DRIER AIR JUST TO THE WEST OF THE WYOMING STATE LINE. THIS
BOUNDARY SHOULD BE THE FOCAL POINT FOR STRONG CONVECTION AS THE
AFTERNOON PROGRESSES. SPC HAS THIS AREA IN SLIGHT RISK AND WOULD
NOT BE SURPRISED TO SEE WATCH LATER TODAY. CURRENT LAPS DATA
SHOWING CAPE VALUES ALREADY OVER 1500 IN THE PANHANDLE WITH SOME
AREAS OVER 3000.LIFTED INDEX OF MINUS 6.

RADAR BEGINNING TO SHOW STORMS DEVELOPING IN WESTERN CARBON COUNTY
AND IN NORTHERN PLATTE COUNTY. LIGHTNING DETECTION SHOWING SOME
STRIKES WITH THIS ACTIVITY.

STORMS THAT DEVELOP THIS AFTERNOON AND EVENING GENERALLY EAST OF
INTERSTATE 25 AND ESPECIALLY IN THE PANHANDLE DEFINITELY SHOULD BE
CAPABLE OF PRODUCING LARGE HAIL AND STRONG WINDS. IN EXTREME
EASTERN AREAS OF THE CWA AN ISOLATED TORNADO WOULD NOT BE OUT OF
THE QUESTION.

STORMS WILL CONTINUE THIS EVENING AND SHOWERS PERSIST OVERNIGHT.

COOLER TEMPERATURES EXPECTED BOTH SUNDAY AND MONDAY AS UPPER
TROUGH MOVES ACROSS THE REGION. THIS SYSTEM SHOULD KEEP THE THE
AREA UNSETTLED AND WILL CONTINUE CHANCES OF RAIN IN THE FORECAST.

.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 1241 PM MDT SAT MAY 18 2013

UPPER TROUGH OVER THE CENTRAL CONUS WILL CONTINUE TO BRING
WRAPAROUND RAIN SHOWERS TO MUCH OF THE FORECAST AREA MONDAY NIGHT
THROUGH TUESDAY WITH CONTINUED COOLER TEMPERATURES. SHORTWAVE
RIDGING WILL BUILD OVERHEAD FOR WEDNESDAY WITH WARMER BUT MUCH
DRIER CONDITIONS...EXCEPT FOR A SLIGHT CHANCE FOR THUNDERSTORMS OVER
THE MOUNTAINS OUT WEST. FLOW ALOFT WILL RETURN TO A MORE
SOUTHWESTERLY COMPONENT FOR THE END OF THE WEEK INTO THE WEEKEND
WITH INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS TO MUCH OF
THE FORECAST AREA.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 1043 PM MDT SAT MAY 18 2013

ACTIVE WEATHER THE NEXT 24 HOURS AS A SLOW MOVING LOW PRESSURE
SYSTEM MOVES ACROSS THE AREA. LOOKING AT LOWERING CIGS SUNDAY MORNING
IN THE PANHANDLE...ESPECIALLY KCDR...KAIA AND KSNY. KCDR AND KAIA
HAVE THE NEST CHANCES OF GOING DOWN AS FORECAST BY THE LATEST HRRR
MODEL. THE OTHER AERODROME THAT COULD GO DOWN IS KRWL EARLY THIS
MORNING. HAVE INTRODUCED IFR AT THESE THREE AIRPORTS...KRWL...KCDR
AND KAIA WITHIN THE NEXT 6 HOURS. WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY SUNDAY AS THE LOW TURNS WINDS NORTHERLY THEN
NORTHEASTERLY. THESE WINDS COULD BE QUITE STRONG IN THE PANHANDLE
SUNDAY AFTERNOON AND EVENING.

&&

.FIRE WEATHER...
ISSUED AT 1241 PM MDT SAT MAY 18 2013

NO FIRE WEATHER CONCERNS AS UNSETTLED WEATHER SHOULD KEEP THE
RELATIVE HUMIDITIES ABOVE CRITICAL VALUES. TEMPERATURES WILL BE
COOLER AND CHANCES OF PRECIPITATION WILL CONTINUE THROUGH MONDAY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

UPDATE...CLAYCOMB
SHORT TERM...GRIFFITH
LONG TERM...RJM
AVIATION...CLAYCOMB
FIRE WEATHER...GRIFFITH