Area Forecast Discussion
Issued by NWS Cheyenne, WY

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000
FXUS65 KCYS 101101 CCA
AFDCYS

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE CHEYENNE WY
459 AM MDT THU JUL 10 2014

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 247 AM MDT THU JUL 10 2014

THE MODELS CONTINUE TO SHOW INCREASING SUBTROPICAL MOISTURE MOVING
INTO THE REGION FROM THE SOUTH AND WEST THROUGH FRIDAY. THIS
ABUNDANT MONSOONAL MOISTURE CAN BE SEEN ON IR IMAGERY WITH
WIDESPREAD MIDLVL CLOUD COVER ACROSS UTAH AND EASTERN NEVADA. AS
THE 500MB HIGH CENTER SHIFTS EASTWARD TODAY TO NORTHERN NEW
MEXICO...FLOW ALOFT BECOMES MORE WEST-TO-SOUTHWEST...WHICH DRAWS
THE MONSOONAL MOISTURE ACROSS THE CWA. PW VALUES INCREASE TO
AROUND 1 INCH BY THIS AFTN OVER ALMOST THE ENTIRE CWA. WITH THE
INCREASING SUBTROPICAL MOISTURE...GENERALLY HAVE 30-40 PERCENT
POPS THIS AFTN. INSTABILITY OVER THE PLAINS IS LESS THAN YESTERDAY
WITH MOST AREAS SEEING CAPE VALUES LESS THAN 1000 J/KG. THE
EXCEPTION WOULD BE THE FAR NORTHERN NEBRASKA PANHANDLE WHERE CAPES
COULD GET UP TO 1500 J/KG. SINCE FLOW ALOFT IS ALSO HIGHER UP
THERE...RESULTING IN BULK SHEAR OF 30-35 KTS...WILL HAVE TO
MONITOR THE POTENTIAL FOR AN ISOLATED STRONG TO SVR STORM. THE SPC
DOES INCLUDE MUCH OF THE NORTHERN PANHANDLE IN A SLIGHT RISK FOR
THIS AFTN. TEMPS WILL CONTINUE TO BE SLIGHTLY ABOVE NORMAL...WITH
MOST LOWER ELEVATION LOCATIONS IN THE MID 80S TO LOW 90S.

NO SIGNIFICANT CHANGES MADE TO THE FCST ON FRI...IT STILL LOOKS
LIKE STORMS WILL BE MOST WIDESPREAD AND WETTEST ON THIS DAY. A
WEAK SFC BOUNDARY PUSHES ACROSS THE PLAINS DURING THE MORNING AND
STALLS ALONG THE LARAMIE RANGE IN THE AFTN. 55-60F SFC DEWPOINTS
WILL PUSH UP ALONG THE LARAMIE RANGE...WHICH IS REALLY HIGH FOR
SOUTHEAST WY. PW VALUES RISE FURTHER WITH MANY AREAS TO THE EAST
OF THE LARAMIE RANGE IN THE 1.25-1.4 INCH RANGE. SOUNDINGS ON FRI
AFTN HAVE A TROPICAL LOOK TO THEM WITH A DEEP MOIST LAYER AND WEAK
MIDLVL LAPSE RATES. WILL DEFINITELY HAVE TO WATCH FOR HEAVY RAIN
AND FLASH FLOODING SINCE THESE STORMS WILL BE EFFICIENT RAIN
PRODUCERS. STEERING FLOW IS GENERALLY 15-20 KTS. TEMPS ON FRI WILL
BE ABOUT 5-10 DEGREES COOLER WITH A LOT OF CLOUD COVER. MOISTURE
LEVELS CONTINUE TO REMAIN QUITE HIGH ON SAT WITH AT LEAST SCT
STORMS ...HOWEVER NOT EXPECTING AS MUCH COVERAGE AS FRI WITH
HEIGHTS ALOFT BEGINNING TO RISE. WHILE SMALL HAIL CAN NOT BE
RULED OUT WITH THE STRONGER TSTMS ON FRI AND SAT...THE MARGINAL
INSTABILITY AND SHEAR WILL KEEP THE SVR THREAT RATHER LOW.

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 247 AM MDT THU JUL 10 2014

THE LATEST MEDIUM RANGE MODEL GUIDANCE DEPICTS A GENERAL NORTHWEST
FLOW ALOFT AS THE CWA IS WEDGED BETWEEN A MEAN TROUGH TO THE EAST AND
RIDGE TO THE WEST. SUBTROPICAL MOISTURE WILL BE TRANSPORTED OVER AND
DOWNSTREAM OF THE WESTERN CONUS RIDGE. A QUASI-STATIONARY SURFACE
BOUNDARY ALONG THE FRONT RANGE SUNDAY WILL PROVIDE FOCUS FOR SCATTERED
MAINLY AFTERNOON/EVENING CONVECTION. A REINFORCEMENT OF COOLER CANADIAN
AIR WILL SURGE SOUTHWARD THROUGH THE NORTH CENTRAL CONUS EARLY NEXT
WEEK. THE LEADING EDGE OF THIS AIR MASS WILL ONCE AGAIN STALL ALONG
THE FRONT RANGE WITH ADEQUATE MOISTURE AND UPSLOPE FOR SCATTERED
CONVECTION. SOMEWHAT DRIER AIR WILL ADVECT SOUTHWEST INTO THE PLAINS
BY MIDWEEK WITH MORE ISOLATED CONVECTION. NEAR SEASONAL TEMPERATURES
SUNDAY AND MONDAY WILL COOL TO BELOW AVERAGE TUESDAY AND WEDNESDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 247 AM MDT THU JUL 10 2014...CORRECTED

ASIDE FROM SOME EARLY MORNING LOW CEILINGS FROM LUSK TO CHADRON
AND ALLIANCE...VFR WILL PREVAIL THROUGH LATE MORNING. GREATER
SHOWER/TSTORM COVERAGE THIS AFTERNOON/EVENING PRODUCING LOCALIZED
MVFR TO IFR IN HEAVY RAIN/GUSTY WINDS. CONFIDENCE NOT HIGH ENOUGH
FOR TSTORM TEMPO OR PREVAILING SO WILL CONTINUE WITH VCTS.

&&

.FIRE WEATHER...
ISSUED AT 247 AM MDT THU JUL 10 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH THE WEEKEND. INCREASING
MONSOONAL MOISTURE WILL PRODUCE MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS TODAY AND FRIDAY. THE BEST CHANCE OF WETTING RAINS
WILL BE ON FRIDAY. MINIMUM AFTERNOON HUMIDITY VALUES WILL
GENERALLY STAY ABOVE 30 PERCENT EACH AFTERNOON THROUGH THE WEEKEND
DUE TO THE ELEVATED MOISTURE LEVELS.

&&

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

$$

SHORT TERM...FINCH
LONG TERM...JAMSKI
AVIATION...JAMSKI
FIRE WEATHER...FINCH






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