Area Forecast Discussion
Issued by NWS Cheyenne, WY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 49 50

000
FXUS65 KCYS 272330
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
530 PM MDT WED MAY 27 2015

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED MAY 27 2015

AFTERNOON WATER VAPOR LOOP SHOWED A FAIRLY AMPLIFIED LARGE SCALE
FLOW ACROSS THE LOWER 48. ONE TROUGH WAS PROGRESS EAST OF THE MS
RIVER VALLEY...WITH THE OTHER OVER THE INTERMOUNTAIN WEST. SEVERAL
UPPER LEVEL DISTURBANCES WERE EJECTING NORTHEAST ACROSS THE ROCKY
MOUNTAINS AND HIGH PLAINS. A SURFACE TROUGH EXTENDED NORTH-SOUTH
THROUGH THE PLAINS OF WY AND CO...WITH HIGHER INSTABILITY AND
TO THE EAST. ISOLATED TSTORMS DEVELOPED BEFORE NOON OVER SOUTHEAST
WY AND INCREASED IN COVERAGE AND INTENSITY OVER WESTERN NE. WHILE
THE SEVERE THREAT WILL BE FOCUSED TO THE SOUTHEAST OF THE CWA...
STRONG TSTORMS PRODUCING HAIL UP TO HALF INCH...HEAVY RAIN AND
GUSTY WINDS WILL BE A THREAT FOR WESTERN NE THROUGH LATE AFTERNOON.

TODAYS DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT PROGGING
THE UPPER TROUGH TO THE WEST TO PROGRESS EAST TOWARD THE FRONT RANGE
THROUGH THURSDAY AND EAST INTO THE GREAT PLAINS ON FRIDAY. ACTIVE
SOUTHWEST FLOW ALOFT...MOISTURE AND INSTABILITY WILL BREW SCATTERED
SHOWERS AND TSTORMS THURSDAY. WHILE THE SEVERE WEATHER THREAT SHIFTS
EAST INTO THE CENTRAL GREAT PLAINS THURSDAY...CANNOT RULE OUT A FEW
STRONG TSTORMS FOR WESTERN NE IN THE AFTERNOON AND EVENING. MODELS
HOLD ONTO GOOD CHANCES FOR SHOWERS THURSDAY NIGHT AND FRIDAY AS A
PACIFIC COLD FRONT MAKES IT WAY EAST ACROSS THE CWA. SEASONABLE
TEMPERATURES /MID 60-MID 70S/ ARE PREDICTED THURSDAY. LESS INSTABILITY
FRIDAY WITH THE PASSAGE OF THE COLD FRONT SO ONLY ISOLATED TSTORMS
EXPECTED. HIGH TEMPERATURES FRIDAY WILL COOL TO ABOUT 10 DEGREES
BELOW SEASONAL NORMALS.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM MDT WED MAY 27 2015

UPPER RIDGING WILL MOVE ACROSS THE REGION OVER THE WEEKEND WHICH
SHOULD ACT TO REDUCE CONVECTIVE ACTIVITY SOME. MAINLY DRY SATURDAY
THEN A FEW SHOWERS/TSTMS SUNDAY AFTERNOON MAINLY OVER AND NEAR THE
SOUTHERN MTNS. TEMPERATURES WARMING BOTH DAYS AS HEIGHTS RISE IN
ASSOCIATION WITH THE UPPER RIDGE. A MORE TYPICAL LATE SPRING PATTERN
THEN SETS UP FOR NEXT WEEK WITH AND UPPER TROF TO THE WEST AND SW
FLOW ALOFT OVER THE CWA. THIS WILL KEEP WARM TEMPS IN PLACE WHILE
WEAK IMPULSES LIFT NORTHEAST ACROSS THE CWA AHEAD OF THE UPPER
TROF AND INTERACT WITH AFTERNOON AND EVENING INSTABILITY TO PRODUCE
SCTD SHOWERS AND TSTMS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 526 PM MDT WED MAY 27 2015

SHOWERS AND THUNDERSTORMS HAVE MOSTLY ENDED ACROSS THE AREA WITH
SCATTERED MID LEVEL CLOUDS REMAINING. COULD BE AN ISOLATED SHOWER
THROUGH 06Z...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN
TAFS. VFR CONDITIONS WILL PREVAIL THROUGH THE NIGHT...EXCEPT
PERHAPS FROM SNY TO AIA WHERE BRIEF IFR CIGS WILL BE POSSIBLE.
ANOTHER ROUND OF SCATTERED SHOWERS AND TSTMS WILL DEVELOP AFTER
18Z THURS.

&&

.FIRE WEATHER...
ISSUED AT 236 PM MDT WED MAY 27 2015

SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH FRIDAY.
WETTING RAINS ARE ANTICIPATED WITH THIS ACTIVITY...AND WILL PRECLUDE
FIRE WEATHER CONCERNS. TEMPERATURES TODAY AND THURSDAY MODERATE TO
SEASONAL NORMALS...BUT WILL COOL TO BELOW NORMAL FRIDAY FOLLOWING
THE PASSAGE OF A COLD FRONT. DRIER AND WARMER CONDITIONS WILL RETURN
THIS WEEKEND. THE EXCEPTION WILL BE ISOLATED AFTERNOON THUNDERSTORMS
OVER THE MOUNTAINS DUE WEAK INSTABILITY AND OROGRAPHIC LIFT.

&&

.HYDROLOGY...
ISSUED AT 236 PM MDT WED MAY 27 2015

MINOR FLOODING CONTINUES ON THE LARAMIE RIVER AT LARAMIE WY AND THE
RIVER WILL REMAIN STEADY NEAR 7.5 FT THROUGH THE WEEKEND. UPSTREAM
WATER RELEASES AT GRAYROCKS HAVE BEEN REDUCED WITH THE STAGE NEAR
FORT LARAMIE WY FALLING BUT REMAINING ABOVE FLOOD STAGE FOR THE NEXT
SEVERAL DAYS. ALONG THE LOWER NORTH PLATTE RIVER...HENRY NE WAS
CRESTING TODAY NEAR 5.5 FT THEN GRADUALLY FALLING. MINOR FLOODING
WAS OCCURRING NEAR MITCHELL NE AND THE RIVER IS FORECAST TO RISE TO
8.8 FT THURSDAY AFTERNOON. AT MINITARE NE...HIGH WATER LEVELS WILL
CONTINUE BUT REMAIN BELOW FLOOD STAGE. THE BASIN AVERAGE RAINFALL
FORECAST THROUGH FRIDAY CALLS FOR 0.25 TO 0.75 INCHES OVER THESE
BASINS...WITH LOCALLY HIGHER AMOUNTS POSSIBLE IN THUNDERSTORMS. THE
RIVER FORECASTS ARE SUBJECT TO CHANGE DEPENDING ON EXACT LOCATION OF
CONVECTION BUT GIVEN THE RANDOM COVERAGE...ANY ADDITIONAL RUNOFF
WILL NEED TO BE MONITORED.

&&

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

$$

SHORT TERM...MAJ
LONG TERM...RE
AVIATION...ZF
FIRE WEATHER...MAJ
HYDROLOGY...MAJ/SML



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