Area Forecast Discussion
Issued by NWS Cheyenne, WY

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000
FXUS65 KCYS 031003
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
403 AM MDT FRI JUL 3 2015

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 335 AM MDT FRI JUL 3 2015

CURRENT KCYS RADAR LOOP SHOWS CONVECTION LINGERING INTO EARLY
THIS MORNING ONCE AGAIN AS A 75 KNOT JET STREAK ALOFT TRANSLATES
INTO SOUTHEAST WYOMING FROM THE NORTH. A PRETTY STRONG CLUSTER IS
CURRENTLY LOCATED NEAR FORT LARAMIE AND WHEATLAND...MOVING
SOUTHEAST. BELIEVE THESE ISOLATED CELLS WILL CONTINUE OVER THE
NEXT FEW HOURS AS THEY MOVE SOUTHWARD INTO COLORADO. CAN NOT RULE
OUT MORE CELLS DEVELOPING JUST EAST OF THE LARAMIE RANGE THIS
MORNING AS WELL DUE TO ELEVATED CAPE. EXPECT A BRIEF LULL IN THE
THUNDERSTORM ACTIVITY SOMETIME LATER THIS MORNING THROUGH NOON
TODAY. HIGH TEMPERATURES WILL BE WARM FOR THE BEGINNING OF THE
HOLIDAY WEEKEND...WITH READINGS IN THE 80S. THUNDERSTORMS WILL
REDEVELOP BY THIS AFTERNOON WITH A FEW BECOMING STRONG LATE THIS
AFTERNOON. KEPT POP BETWEEN 20 TO 25 PERCENT OUTSIDE THE MOUNTAINS
FOR ISOLATED TO WIDELY SCT COVERAGE INTO TONIGHT. WOULD NOT BE
SURPRISED IF THIS ACTIVITY CONTINUES THROUGH THE NIGHT OVER THE
HIGH PLAINS FRIDAY NIGHT DUE TO JET DYNAMICS ALOFT.

NEXT POTENTIAL FOR STRONG OR SEVERE THUNDERSTORMS WILL BE
SATURDAY AS TEMPERATURES INCREASE INTO THE UPPER 80S TO MID 90S
ONCE AGAIN. AMPLE MOISTURE WILL REMAIN OVER THE HIGH PLAINS...AS
IT HAS SINCE MAY WITH DEWPOINTS LIKELY IN THE 50S TO MID 60S.
KEPT POP BETWEEN 10 TO 20 PERCENT FOR NOW DUE TO MODEL
DIFFERENCES...EVEN THOUGH MODEL SOUNDINGS DO INDICATE HIGH CAPE
VALUES OVER 2000 J/KG AND LOWERING CIN THROUGH THE AFTERNOON OVER
WESTERN NEBRASKA. HOWEVER...ANY TSTORMS MAY BE VERY ISOLATED OR
FURTHER TO THE NORTHEAST DUE TO AN APPROACHING UPPER LEVEL RIDGE
AXIS AND DRIER AIR ALOFT.

ALL MODELS INDICATE AN APPROACHING CANADIAN COLD FRONT DIGGING
SOUTHWARD ON SUNDAY. THIS FRONT IS PRETTY STRONG FOR THIS TIME OF
THE YEAR WITH 700MB TEMPERATURES LOWERING TO 0C LATE ON SUNDAY
JUST NORTH OF THE FORECAST AREA. THIS FRONTAL BOUNDARY WILL
INTERACT WITH UPSLOPE FLOW AND AMPLE LOW TO MIDLEVEL MOISTURE
ACROSS THE AREA...PRODUCING SCATTERED TO NUMEROUS SHOWERS/TSTORMS
THROUGH THE DAY ON SUNDAY. HIGH TEMPERATURES WILL LIKELY OCCUR IN
THE LATE MORNING OR AROUND NOON...AND THEN FALL INTO THE 70S
THROUGH THE DAY. INCREASED POP BETWEEN 30 TO 50 PERCENT FOR THE
HIGH VALLEYS AND HIGH PLAINS...WITH VALUES NEAR 70 PERCENT FOR THE
MOUNTAINS.

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 400 AM MDT FRI JUL 3 2015

WEAK UPPER RIDGE OVER THE SOUTHWEST CONUS WILL FLATTEN OUT SUNDAY
NIGHT AS A RATHER STRONG NORTHERN STREAM WAVE MOVES ACROSS MONTANA
AND INTO THE NORTHERN PLAINS. THE SHORTWAVE TROUGH WILL EXTEND
SOUTHWARD INTO WYOMING AND NEBRASKA SUNDAY NIGHT. THIS TROUGH WILL
PUSH COOLER AIR INTO THE AREA AND LIKELY PRODUCE SHOWERS AND
THUNDERSTORMS ACROSS MUCH OF THE AREA SUNDAY NIGHT.

MONDAY WILL BE ON THE COOLER SIDE AS RAIN COOLED AIR AND LIGHT
EASTERLY UPSLOPE FLOW WILL BE IN PLACE. CHANCES FOR SHOWERS AND
THUNDERSTORMS EAST OF THE LARAMIE RANGE WILL BE SUPPRESSED MONDAY
BY A STABLE LOW LEVEL AIR BUT ALONG AND WEST OF THE LARAMIE RANGE
DAYTIME HEATING WILL LIKELY PRODUCE A FEW SHOWERS AND
THUNDERSTORM.

TEMPERATURES TO REBOUND TUESDAY AS WESTERLY FLOW ALOFT DEVELOPS
BUT LOW LEVEL WINDS WILL REMAIN SOUTHERLY WITH A SURFACE LEE
TROUGH ALONG THE ROCKIES. THIS MEANS THE CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE. COULD EVEN SEE ANOTHER SHORTWAVE
TROUGH IMPACT THE AREA BY TUESDAY NIGHT INTO WEDNESDAY WITH EVEN
MORE SHOWERS AND THUNDERSTORMS AND ANOTHER SHOT OF COOL AIR.

AT THIS TIME NOT SEEING ANY BIG CHANCES IN THE OVER ALL PATTERN
THAT WILL LEAD TO DRIER CONDITIONS. IF ANYTHING LATE NEXT WEEK
COULD BE EVEN WETTER. MODELS ARE SHOWING THE CUTOFF LOW CURRENTLY
WEST OF THE CALIFORNIA COAST SHIFTING EAST TO NORTHEAST ACROSS THE
WESTERN CONUS LATE NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 400 AM MDT FRI JUL 3 2015

A FEW THUNDERSTORMS CONTINUE TO MOVE ACROSS FAR SOUTHEAST WYOMING
NEAR THE NEBRASKA BORDER. STORMS SHOULD MOVE SOUTHWARD INTO COLORADO
SOMETIME AROUND 12Z. PATCHY FOG POSSIBLE UNTIL SHORTLY AFTER SUNRISE
IN LOW LYING AND SHELTERED LOCATIONS BUT IMPACTS ON AVIATION SHOULD
BE MINIMAL. ANOTHER ROUND OF ISOLATED THUNDERSTORMS FOR THIS
AFTERNOON...MAINLY OVER SOUTHEAST WYOMING. GUSTY WINDS AND SMALL
HAIL IS THE MAIN CONCERN WITH ANY THUNDERSTORM ACTIVITY.
THUNDERSTORMS MAY ONCE AGAIN LINGER THROUGH THE OVERNIGHT HOURS
TONIGHT.

&&

.FIRE WEATHER...
ISSUED AT 246 AM MDT FRI JUL 3 2015

NO FIRE WEATHER CONCERNS IN THE FORESEEABLE FUTURE WITH NEARLY
DAILY CHANCES FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS. WINDS WILL REMAIN GENERALLY LIGHT...THOUGH BRIEFLY
GUSTY AROUND STORMS. A MONSOON PATTERN MAY SET UP NEXT WEEK WHICH
WILL KEEP CHANCES FOR SHOWERS AND STORMS IN THE FORECAST.

&&

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

&&

$$

SHORT TERM...TJT
LONG TERM...SML
AVIATION...SML
FIRE WEATHER...TJT



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