335
FXUS65 KCYS 031155
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
455 AM MST MON FEB 3 2025
KEY MESSAGES
- HIGH WINDS CONTINUE ACROSS PORTIONS OF SOUTHEAST WYOMING THIS
MORNING WITH GUSTS OVER 60 MPH.
- SPLIT TEMPERATURES FROM A SAGGING FRONTAL BOUNDARY EXPECTED TO
START THE WEEK WITH CHILLY, SUB-FREEZING HIGHS FOR
NORTHEASTERN PORTIONS OF THE CWA, WHILE THE REST OF THE LOWER
ELEVATIONS SEE SEASONABLY WARM TEMPERATURES WITH MILD
AFTERNOON HIGHS.
- WIDESPREAD ELEVATED TO STRONG WINDS CONTINUE INTO NEXT WEEK
WITH MILD TEMPERATURES.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 351 AM MST MON FEB 3 2025
AT THE SURFACE, A WEAK FRONTAL BOUNDARY IS SLOWLY DRAGGING SOUTHWARD
THROUGH OUR FORECAST AREA. THERE IS A WIDE SWATH OF TEMPERATURES
ACROSS THE AREA AS CHADRON IS IN THE LOW 20'S, CHEYENNE IS STILL IN
THE 50'S AND RAWLINS IS IN THE 40'S. THIS FRONT WILL ALSO CAUSE A
WIND SHIFT FROM A WESTERN FLOW TO A MORE NORTHERLY FLOW BEHIND THE
FRONT. DESPITE THE 700MB WINDS STILL MAINTAIN SPEEDS BETWEEN 55 TO
65KTS PAST 18Z. THE FRONTAL SHIFT WILL CREATE A SORT OF DISCONNECT
FROM THOSE HIGHER WINDS AND EFFECTIVELY NOT ALLOWING THOSE HIGHER
WINDS TO MIX DOWN TO THE SURFACE. SO THE DECISION WAS MADE TO ALLOW
THE HIGH WIND WARNINGS TO EXPIRE AT THEIR SLOTTED TIMES AND NOT BE
EXTENDED ON THIS SHIFT. HOWEVER, THE AREA ESPECIALLY IN THE WIND
PRONES WILL SEE ELEVATED GUSTY WINDS JUST NOT WARNING CRITERIA
WINDS. TEMPERATURES ARE EXTREMELY TRICKY BECAUSE OF THIS FRONTAL
BOUNDARY AND THE FILTERING OF COOLER AIR BEHIND IT. THE HREF SHOWS A
VERY TIGHT GRADIENT FOR THE PROBABILITY OF THE HIGH TEMPERATURE
BEING LESS THAN 32F FOR TODAY. BEHIND THE FRONT IS 100 PERCENT
CHANCE AND IN FRONT OF THE FRONT IS 0 PERCENT. ALONG A LINE FROM
CASPER TO SCOTTSBLUFF, THERE IS A GRADIENT FROM 70 TO 40 PERCENT
CHANCE OF THE TEMPERATURES BEING BELOW 32F RIGHT WHERE THE HI-RES
ENSEMBLES THINK HOW FAR SOUTH THE FRONT WILL SHIFT. TO ADD MORE
PERSPECTIVE SIDNEY, NE HAS A 10 PERCENT CHANCE OF HAVING A HIGH
TEMPERATURE OF LESS THAN 32 DEGREES TODAY WITH CHEYENNE, RAWLINS,
AND LARAMIE HAVING A ZERO CHANCE. NO MODEL REALLY HAD A GREAT HANDLE
ON THIS FRONT SO A BLEND OF BCCONSHORT AND NBM90 WAS USED. THAT WAY
THE DOWNSLOPING ON TOWNS AHEAD OF THE FRONT WAS SOMEWHAT CAPTURED
AND SOME RESEMBLANCE OF THE FRONT WAS ALSO CAPTURED. AS I'M
CURRENTLY FIGHTING FOR MY LIFE TRYING TO GET ACCURATE TEMPERATURES
FOR TODAY, THE LIKELY SCENARIO THROUGHOUT THE DAY WILL BE THE TEMPS
BEING RAISED TO TRY TO CAPTURE THE DOWNSLOPE AND THE DIURNAL TREND
AHEAD OF THE FRONT AND THE COOLER TEMPS AND DIURNAL TREND BEHIND THE
FRONT. LOOKING AHEAD TO TUESDAY, THE FLOW WILL BE OUT OF THE SOUTH
AS THE UPPER LEVEL RIDGE PUSHES INTO OUR REGION. THERE WILL BE A
PLUME OF MOISTURE THAT WILL BE ADVECTED INTO OUR REGION. HOWEVER,
ONLY THE SIERRA MADRES AND SNOWY MOUNTAINS WILL LIKELY SEE SOME VERY
LIGHT SNOW SHOWERS DUE TO UPSLOPE. OTHERWISE EVERYWHERE ELSE LOOKS
DRY IN THE SHORT TERM.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
ISSUED AT 351 AM MST MON FEB 3 2025
THE LONG TERM STARTS OFF WITH A BANG, WITH HIGH WINDS POSSIBLE ON
WEDNESDAY. A WEAK SHORTWAVE TRAVERSING THE ZONAL FLOW ALOFT WILL
LEAD TO A SLIGHT TIGHTENING OF MSLP GRADIENTS OVER THE CWA. WINDS
ALOFT WILL RESPOND, INCREASING TO 50 TO 60 KTS OVER A GOOD CHUNK OF
THE FORECAST AREA DURING THE DAY WEDNESDAY. GOOD SUBSIDENCE OVER THE
WIND PRONES AREAS ARE LIKELY TO BRING THESE WINDS DOWN TO THE
SURFACE, WITH IN-HOUSE GUIDANCE ALREADY PINGING THE WIND PRONES WITH
A 50 PERCENT CHANCE OF HIGH WINDS. THIS WILL BE A QUICK HIGH WIND
EVENT WITH WINDS RELAXING BY THE EVENING HOURS WEDNESDAY. FOLLOWING
WEDNESDAY, EXPECT WINDS TO REMAIN BREEZY ACROSS SOUTHEAST WYOMING
THROUGH THE END OF THE WORK WEEK DUE TO A 250 MB JET SITTING OVER
WYOMING.
TEMPERATURES THROUGHOUT THE WEEK WILL GRADUALLY COOL AFTER
WEDNESDAY. EXPECT A WARM, ABOVE AVERAGE DAY ON WEDNESDAY AS 700 MB
TEMPERATURES SIT ABOVE 0C, WHICH IS IN THE 90TH PERCENTILE FOR NAEFS
CLIMATOLOGY. COMBINED WITH WARM, DOWNSLOPING WINDS, TEMPERATURES
WILL SKYROCKET INTO THE 50S AND MID 60S. AFTER WEDNESDAY,
TEMPERATURES WILL GRADUALLY COOL OFF AS 700 MB TEMPERATURES FALL
BACK BELOW 0C. THE COLDEST TEMPERATURES ARE LIKELY THIS WEEKEND AS A
STRONG FRONT MOVES INTO WYOMING.
WHILE UNDER THE CURRENT ZONAL FLOW PATTERN, PRECIPITATION CHANCES
LOOK FAIRLY LIMITED FOR THE PLAINS AS BETTER MOISTURE REMAINS
FURTHER NORTH. SOME MOUNTAIN SNOW COULD BE POSSIBLE THROUGH THE END
OF THE WORK WEEK THANKS TO OROGRAPHIC LIFT AND SOME MID-LEVEL
MOISTURE, WITH A FEW INCHES OF SNOW ACCUMULATION POSSIBLE. A
STRONGER SHORTWAVE WILL MOVE INTO THE CWA SATURDAY, BRINGING AMPLE
MOISTURE WHICH COULD RESULT IN WIDESPREAD LIGHT SNOWFALL
ACCUMULATIONS ACROSS THE PLAINS.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 453 AM MST MON FEB 3 2025
SURFACE OBSERVATIONS SHOW A COLD FRONT MOVING INTO THE CWA, WITH
KCDR, KAIA, AND KBFF ALREADY BEHIND THE FRONT. WINDS AT THESE
LOCATIONS HAVE SWITCHED OUT OF THE NORTH WITH GUSTS OVER 20 KTS.
WINDS REMAIN STRONG AT SOUTHEAST WYOMING TERMINALS WITH GUSTS OVER
30 KTS. THIS FRONT HAS BROUGHT LOW CIGS AND SOME BR TO KCDR AND
KAIA. IFR CIGS ARE EXPECTED TO LINGER AROUND KCDR AND KAIA THIS
MORNING, BUT SHOULD LIFT BY THE AFTERNOON FOR KAIA. KCDR WILL LIKELY
BE DOWN IN LOW CIGS MOST OF THE DAY.
CYS WATCHES/WARNINGS/ADVISORIES
WY...HIGH WIND WARNING UNTIL 8 AM MST THIS MORNING FOR WYZ101-
106>108-115>118.
HIGH WIND WARNING UNTIL 11 AM MST THIS MORNING FOR WYZ104-109-
110-113.
NE...NONE.
SHORT TERM...MM
LONG TERM...SF
AVIATION...SF
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