Area Forecast Discussion
Issued by NWS Cheyenne, WY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
292
FXUS65 KCYS 160354
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
954 PM MDT FRI MAY 15 2015

.UPDATE...
ISSUED AT 815 PM MDT FRI MAY 15 2015

THE FIRST SIGNIFICANT SEVERE WEATHER EVENT OF THE SPRING SEASON
IS FINALLY WINDING DOWN THIS EVENING. WATER VAPOR IMAGERY SHOWED
THE BROAD UPPER TROUGH OVER THE WESTERN CONUS WITH A DISTINCT
CLOSED CIRCULATION OVER NORTHWEST NV. THE SURFACE ANALYSIS PLACED
THE LOW PRESSURE CENTER OVER SOUTHWEST NE WITH A WARM FRONT
EXTENDING ACROSS NORTHERN NE AND IA AND A COLD FRONT SOUTH ACROSS
EASTERN CO AND NM. AS PREDICTED...MOST OF THE INTENSE CONVECTION
DEVELOPED NORTH AND EAST OF THE TRIPLE POINT WHERE BULK SHEAR AND
INSTABILITY WAS GREATEST. THERE WERE NUMEROUS LARGE HAIL REPORTS...
FUNNEL CLOUDS...URBAN/SMALL STREAM FLOODING...AND A CONFIRMED
TORNADO. REGIONAL RADARS INDICATED THAT THE SEVERE THREAT HAS
SHIFTED EAST INTO WEST/CENTRAL NE AN SOUTHWEST SD THIS EVENING.
TORNADO WATCH #172 EXPIRED AT 8 PM. REMAINDER OF THIS EVENING...
LEFT CHANCE-LIKELY POPS FOR FAR EASTERN ZONES...WITH SLIGHT
CHANCE POPS ELSEWHERE AS RADARS SHOW LINGERING LIGHTER CONVECTION
MOVING NORTHEAST FROM NORTHERN CO.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 311 PM MDT FRI MAY 15 2015

DISCUSSION WILL BE RATHER ABBREVIATED DUE TO SEVERE STORMS NOW
AFFECTING PARTS OF THE AREA.

UPPER LOW OVER THE SW CONUS WILL MOVE SLOWLY NORTHEAST OVER THE
NEXT COUPLE DAYS WITH SHORTWAVES PASSING OVER THE CWA AT TIMES.
STORMS FIRING UP OVER THE CWA NOW WITH STRONGEST STORMS OVER THE
PANHANDLE INTO FAR SE WY WHERE INSTABILITY IS GREATEST WITH CAPES
1500-2500 J/KG. EXPECT THIS ACTIVITY TO CONTINUE INTO THIS EVENING
AS A SFC TROF MOVES EAST...WITH THE STRONGEST ACTIVITY EXPECTED TO
EXIT TO THE NORTHEAST BY MID EVENING AS THE SFC TROF MOVES FARTHER
EAST. RESIDUAL SHOWERS EXPECTED INTO THE LATE EVENING THEN ENDING
AS ONE WAVE LIFTS TO THE NORTHEAST OF THE AREA.

MAINLY DRY SAT MORNING THEN APPROACH OF NEXT SHORTWAVE SHOULD
INITIATE ANOTHER ROUND OF SHOWERS AND A FEW STORMS MAINLY OVER THE
SE HALF OF THE CWA. INSTABILITIES RATHER WEAK SO ANY STORMS SHOULD
BE WEAK AS WELL. ACTIVITY SHOULD END SAT EVENING THEN RETURN ONCE
AGAIN SUNDAY AFTERNOON. COOL FRONT WILL DROP SE ACROSS THE CWA
SUNDAY AFTERNOON AND EVENING. TEMPS REMAINING ON THE MILD SIDE
THROUGH THE WEEKEND.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 311 PM MDT FRI MAY 15 2015

RATHER COOL AND UNSETTLED EXTENDED PERIOD CONTINUES TO BE SHOWN BY
THE MODELS. MONDAY WILL LIKELY BE THE DRIEST DAY ACROSS THE REGION
WITH THE RIDGING ALOFT AND VERY LIMITED INSTABILITY (MAINLY OUT
WEST). THE BEST CHANCE OF SHOWERS WILL BE ALONG AND WEST OF THE
LARAMIE RANGE. SOUTHEASTERLY SFC WINDS WILL PUSH HIGHER DEWPOINTS
TOWARD THE LARAMIE RANGE BY TUESDAY MORNING. AN UPPER LEVEL
SYSTEM OVER CALIFORNIA ON MON WITH MOVE QUICKLY NORTHEASTWARD ON
TUESDAY. UPPER LEVEL DIVERGENCE AND DEEP LAYER ASCENT WILL
INCREASE BY TUESDAY AFTN AND EVENING AND INTERACT WITH GOOD
MOISTURE (PW VALUES ARE ABOVE 0.75 INCHES) TO PRODUCE WIDESPREAD
RAIN AND MAYBE AN ISOLATED TSTM. LOOKING MORE LIKE A STRATIFORM
EVENT...AND STRONG STORMS WOULD NOT BE A CONCERN WITH THE GFS
SHOWING REALLY NO CAPE ACROSS THE PLAINS. WEAK SHORTWAVE WILL BE
IN THE VICINITY OF SOUTHWEST SOUTH DAKOTA ON WED WITH SCATTERED
SHOWERS PERSISTING. THERE IS SOME INDICATION THAT IT WILL DRY OUT
BY THURS...HOWEVER CAN NOT RULE OUT ISOLATED CONVECTION WITH LOW
LEVEL UPSLOPE TO THE EAST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 951 PM MDT FRI MAY 15 2015

VFR PREVAILS...WITH LOCALIZED IFR AT SOME TAF SITES DUE TO
LOW CLOUDS AND FOG THROUGH MID MORNING. BECOMING VFR FRIDAY
MORNING. SCATTERED THUNDERSTORMS DEVELOPING SATURDAY AFTERNOON AND
CONTINUING INTO THE EVENING.

&&

.FIRE WEATHER...
ISSUED AT 311 PM MDT FRI MAY 15 2015

CONCERNS TO REMAIN QUITE LOW INTO EARLY NEXT WEEK WITH CONDITIONS
AND FUELS EXPECTED TO REMAIN NON-CRITICAL. NEARLY DAILY CHANCES
FOR SHOWERS AND A FEW THUNDERSTORMS SEEN INTO EARLY NEXT WEEK.

&&

.HYDROLOGY...
ISSUED 545 PM MDT FRI MAY 15 2015

HIGH WATER LEVELS CONDITIONS WILL CONTINUE ALONG THE LARAMIE RIVER
AT LARAMIE AND FORT LARAMIE THIS WEEKEND. RUNOFF FROM TODAYS STORMS
MAY CAUSE MINOR RISES ALONG THE NORTH PLATTE AND NIOBRARA RIVER
BASINS. FORTUNATELY...COOL THAN NORMAL TEMPERATURES WILL LIMIT
MOUNTAIN SNOWMELT.

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

&&

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

$$

UPDATE...MJ
SHORT TERM...RE
LONG TERM...CAH
AVIATION...RUBIN
FIRE WEATHER...RE
HYDROLOGY...MAJ



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.