070
FXUS65 KCYS 021305
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
605 AM MST SUN FEB 2 2025
KEY MESSAGES
- HIGH WINDS ARE EXPECTED AGAIN TODAY THROUGH MONDAY MORNING.
HIGH WIND WARNINGS HAVE BEEN ISSUED FOR MOST OF SOUTHEAST
WYOMING.
- WINTER STORM WARNINGS CONTINUE FOR THE SIERRA MADRE AND SNOWY
RANGES THROUGH SUNDAY FOR HEAVY ACCUMULATING SNOW AND WINDY
CONDITIONS, ALONGSIDE WINTER WEATHER ADVISORIES FOR RAWLINS
AND THE ARLINGTON AREA.
- WIDESPREAD ELEVATED TO STRONG WINDS CONTINUE INTO NEXT WEEK
WITH MILD TEMPERATURES.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 600 AM MST SUN FEB 2 2025
THE PREVIOUS HIGH WIND WARNINGS THAT ENDED AT 12Z WERE CANCELLED
EARLY SINCE ALL THE GUSTS DROPPED OFF. THE HIGH WIND WATCHES WERE
UPGRADED TO HIGH WIND WARNINGS STARTING AT 5 AM AND 11 AM AND ENDING
AT 8 AM AND 11 AM MONDAY. THE LARAMIE VALLEY (ZONE 115) WAS ADDED
DUE TO MAXED OUT SUBSIDENT VALUES FROM THE NAM AND GFS OMEGA FIELDS.
TO FURTHER OUR CONFIDENCE OF THESE HIGHER GUSTS WITHIN THE VALLEY,
THE LAMP DEPICTED 46 KNOT WIND GUST FOR LARAMIE AIRPORT THIS
AFTERNOON. SO IF THE SIGNAL IS STRONG ENOUGH FOR THE LAMP TO PICK IT
UP IT SHOULD BE IN THE WARNING AS WELL. ALSO THE SKYLINE SENSOR
GUSTED TO 56 MPH OVER AT SARATOGA AT 5320AM SO THE SARATOGA VALLEY
WAS ALSO ADDED TO THE WARNINGS.
THE OVERALL PATTERN REMAINS ZONAL THROUGH MONDAY MORNING. MONDAY
MORNING THE PATTERN CHANGES FROM ZONAL TO A RIDGING PATTERN AS A
THERMAL RIDGE START TO PUSH INTO THE ROCKIES FROM THE PACIFIC
NORTHWEST TO FINISH OUT THE DURATION OF THE SHORT TERM PERIOD.
TODAY, OUR SURFACE WINDS WILL SWAP FROM A SOUTH-SOUTHWEST FLOW TO A
WESTERN FLOW ON THE WESTERN PORTION OF OUR CWA. WHILE IN THE
SOUTHERLY FLOW THE WINDS WILL FAVOR AN UPSLOPE FLOW LEADING TO A FEW
MORE INCHES OF SNOWY FOR THE SIERRA MADRES AND SNOWY MOUNTAINS. IN
ADDITION TO THE UPSLOPE FLOW THERE IS SOME SLIGHT ISENTROPIC ASCENT
OVER CARBON AND ALBANY COUNTY TO ALLOW SUFFICIENT MOISTURE TO BE
LIFTED FOR CONTINUED SNOW DEVELOPMENT. HI-RES COMPOSITE REFLECTIVITY
SHOWS A CONSENSUS FOR A BANDED PRECIP EVENT THIS MORNING ACROSS THE
FORECAST AREA EAST OF I-25 IN AND INTO MAJORITY OF THE PANHANDLE.
SPC MESOANALYSIS SHOWS A THETA-E GRADIENT THAT IS SETUP AND SHIFTS
NORTHWARD TO LINE UP WITH WHERE THE HI-RES MODELS PLACED THE BAND OF
PRECIPITATION IN THE COMPOSITE REFLECTIVITY PRODUCTS. GIVEN THE
WARMER TEMPERATURES AT THE LOWER ELEVATIONS EAST OF I-25, THE PRECIP
MAY COME DOWN AS RAIN OR SNOW THEN TRANSITION TO RAIN THROUGHOUT THE
MORNING FOR AREAS NORTH AND EAST OF LARAMIE COUNTY. MOVING UP
HIGHER INTO THE ATMOSPHERE, A 700MB JET THAT SPANS ACROSS THE CWA
WITH VALUES BETWEEN 60 TO 75 KNOTS WILL HELP FUEL OUR HIGH WINDS FOR
TODAY. THE RAP DOES RELAX THE SURFACE GRADIENT THROUGHOUT THE COURSE
OF THE DAY AS AN UPPER LEVEL TROUGH PUSHES EAST AND WITH A SURFACE
LOW FOLLOWING. HOWEVER, THE GFS AND NAM OMEGA FIELDS RETAIN MAXED
OUT VALUES FOR SUBSIDENT FLOWS OVER SOUTHEAST WYOMING. FOR THE
NEBRASKA PANHANDLE, THE SAME OMEGA FIELDS SHOWED MODERATE TO STRONG
ASCENT FOR THE DURATION. THE 700MB JET COUPLED WITH THE STRONG
DESCENT SHOWN IN THE OMEGA FIELDS PROMPTED THE HIGH WIND WARNINGS
FOR MAJORITY OF THE SOUTHEAST WYOMING AREA WITH AN EXPIRATION TIME
BETWEEN 15 TO 18Z ON MONDAY. OVER THE COURSE OF THE DAY MONDAY, THE
JETSTREAM STARTS TO LIFT NORTH SHIFTING THE ISENTROPIC LIFT AND
700MB TO THE NORTH AS WELL. THE PRECIPITATION CHANCES AND THE HIGH
WINDS WILL GRADUALLY LESSEN OVER THE COURSE OF THE DAY. THIS IS ALSO
WHEN THE THERMAL RIDGE STARTS TO PUSH EAST TO GIVE US A SMALL BREAK
AND DRY OUT STARTING TUESDAY.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED AT 600 AM MST SUN FEB 2 2025
AN ACTIVE WEATHER PATTERN CONTINUES IN THE LONG TERM WITH FAST FLOW
ALOFT CONTRIBUTING TO PROLONGED WINDINESS AND CHANCES FOR
PRECIPITATION.
BROAD UPPER-LEVEL RIDGING OVER CONUS WILL CONTINUE THROUGH MID-WEEK,
CONTRIBUTING TO ABOVE AVERAGE HIGH TEMPERATURES FOR THE CWA. 700 MB
TEMPERATURES ON TUESDAY WILL BE A FEW DEGREES ABOVE 0C, PUTTING
THESE TEMPERATURES ABOVE THE 97.5TH PERCENTILE FOR NAEFS
CLIMATOLOGY. 700 MB TEMPERATURES WILL FALL TO AROUND 0C ON WEDNESDAY
WHICH IS NEAR THE 90TH PERCENTILE FOR CLIMATOLOGY. AS A RESULT, THE
WARMEST TEMPERATURES OF THE WEEK ARE EXPECTED ON THESE DAYS,
WITH HIGHS MAKING IT INTO THE 50S AND 60S FOR MOST OF THE CWA.
THE RIDGE WILL FLATTEN OUT INTO ZONAL FLOW ONCE AGAIN ON
THURSDAY, TRENDING TEMPERATURES BACK DOWN FOR THE END OF THE
WEEK.
WHILE UNDER THE AFOREMENTIONED RIDGE, THE CWA WILL SEE A BREAK
FROM HIGH WINDS. BREEZY CONDITIONS ARE STILL EXPECTED AS WINDS
ALOFT WILL BE ELEVATED, HOWEVER, HIGH WINDS ARE NOT EXPECTED ON
TUESDAY. HIGH WINDS MAY MAKE A BRIEF RETURN ON WEDNESDAY AS A
WEAK SHORTWAVE TRAVERSES THE ROCKIES. 700 MB WINDS WILL INCREASE
TO 60 KTS OVER THE USUAL WIND PRONE AREAS WITH STRONG
SUBSIDENCE. THIS SHORTWAVE WILL CAUSE A BRIEF STRENGTHENING OF
MSLP GRADIENTS WHICH COULD LEAD TO HIGH WINDS WEDNESDAY INTO
WEDNESDAY EVENING. AFTER WEDNESDAY, EXPECT BREEZY CONDITIONS TO
CONTINUE AS A 250 MB JET PUSHES INTO WYOMING AND REMAINS OVER
THE AREA THROUGH THE END OF THE WEEK.
WHILE UNDER THE CURRENT FLOW PATTERN, MULTIPLE PRECIPITATION CHANCES
WILL BE POSSIBLE. THE MOUNTAINS WILL SEE THE BULK OF THE
PRECIPITATION AS MID-LEVEL MOISTURE AND WEST TO SOUTHWEST FLOW
PROVIDE LIFT FOR OROGRAPHIC SNOW GENERATION. THE PROLONGED MOUNTAIN
SNOW COULD LEAD TO IMPRESSIVE TOTALS OVER THE COURSE OF THE WEEK.
THE PLAINS WILL LIKELY STAY DRY THROUGH MOST OF THE WEEK, WITH
MODELS NOT ANTICIPATING PRECIPITATION UNTIL A STRONGER FRONT MOVES
THROUGH FRIDAY NIGHT INTO SATURDAY.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 506 AM MST SUN FEB 2 2025
A TRICKY AVIATION FORECAST IS EXPECTED TODAY WITH STRONG WINDS AND
THE POTENTIAL FOR PRECIPITATION. HI-RES GUIDANCE HAS NOT BEEN
HANDLING THE PRECIPITATION WELL. BOTH RADAR AND MODELS SHOW THAT
PRECIPITATION SHOULD BE FALLING AT SOME TERMINALS AT THE 12Z TAF
ISSUANCE, HOWEVER, OBSERVATIONS ARE NOT REPORTING ANYTHING. DESPITE
THIS, DID PUT MENTIONS OF -SN AT SOME TERMINALS THIS MORNING. IF -SN
DOES OCCUR, EXPECT LOW VISIBILITY AND LOW CIGS WHICH COULD LEAD TO
MVFR OR IFR CONDITIONS. THE OTHER CONCERN TODAY AND INTO TONIGHT
WILL BE THE THREAT OF HIGH WINDS AT SOUTHEAST WYOMING TERMINALS.
GUSTS OVER 50 KTS COULD BE POSSIBLE STARTING THIS AFTERNOON AND
CONTINUING OVERNIGHT. LLWS CAN ALSO BE EXPECTED AT MOST
TERMINALS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...HIGH WIND WARNING FROM 11 AM THIS MORNING TO 8 AM MST MONDAY
FOR WYZ101-106>108-115>118.
HIGH WIND WARNING UNTIL 11 AM MST MONDAY FOR WYZ104-109-110-
113.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR
WYZ109-110.
WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ112-
114.
NE...NONE.
SHORT TERM...MM
LONG TERM...SF
AVIATION...SF
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