581
FXUS65 KCYS 060935
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
335 AM MDT WED AUG 6 2025
KEY MESSAGES
- LARGELY HOT AND DRY CONDITIONS ARE EXPECTED ACROSS THE AREA
THROUGH FRIDAY. AREAS OF SMOKE FROM COLORADO AND ARIZONA
WILDFIRES MAY DRIFT THROUGH THE AREA.
- AN ISOLATED STRONG TO SEVERE THUNDERSTORM CANNOT BE RULED OUT
THIS AFTERNOON, MAINLY IN THE NORTHERN NE PANHANDLE AND EAST
CENTRAL WY.
- RED FLAG WARNINGS REMAIN IN EFFECT THROUGH FRIDAY DUE TO LOW
AFTERNOON RELATIVE HUMIDITY AND POOR OVERNIGHT HUMIDITY
RECOVERIES.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 334 AM MDT WED AUG 6 2025
TODAY, AN UPPER LEVEL RIDGE WILL KEEP THINGS RATHER WARM AND MOSTLY
DRY. A TERRAIN DERIVED DRYLINE WILL KEEP MOST OF SOUTHEAST WYOMING
RETAINING RH VALUES BELOW 15 DURING THE DAY WITH SUBTLE WINDS. THE
RED FLAG WARNING WAS KEPT FOR CARBON COUNTY AS WESTERLY WINDS ARE
EXPECTED TO REMAIN TODAY. THERE IS A MARGINAL RISK FOR SEVERE
THUNDERSTORMS TODAY. THIS IS MOSTLY FOR THE NIOBRARA COUNTY AND THE
NORTHERN PORTION OF THE NEBRASKA PANHANDLE. CAPE IS EXPECTED TO
FLOAT BETWEEN 1500 TO 2000 JOULES WITH MODEST MID-LEVEL LAPSE RATES
AROUND 8.0C/KM. DEWPOINTS FOR THE PANHANDLE LOOK TO REMAIN IN THE
50'S WHILE NIOBRARA LOOKS TO BE INTO UPPER 40'S. THE RAP HAS THE
CONVECTIVE TEMP AROUND 95F, SO THERE'S IS A SLIGHT CHANCE THAT THE
CONVECTIVE INHIBITION COULD BE OVERRIDDEN AND SEVERE STORMS COULD
DEVELOP. THURSDAY, THE RIDGE WILL PEAK OVERHEAD AS A LOW PRESSURE
SYSTEM MOVES INTO THE PACIFIC NORTHWEST. THIS SYSTEM AMPLIFIES THE
RIDGE OVER US INCREASING THE DRY AIR ADVECTION FROM THE DESERT
SOUTHWEST. THE PRESSURE GRADIENT WILL ALSO INCREASE EXPANDING FIRE
WEATHER CONCERNS FOR THE SOUTHEAST WYOMING AREA. AS GUSTY WINDS LOOK
TO BE OCCURRING FOR THURSDAY THE RED FLAG WARNING WAS EXPANDED FOR
CONVERSE AND NIOBRARA COUNTIES FOR THURSDAY AFTERNOON AND EARLY
EVENING AS RH VALUES ARE EXPECTED TO BE BELOW 15 AND THE WIND GUSTS
ARE EXPECTED TO REACH 25 MPH. THURSDAY IS ALSO EXPECTED TO BE THE
WARMEST DAY OF THE WEEK AS 700MB TEMPERATURES ARE EXPECTED RANGE
BETWEEN 18 AND 21 DEGREES. THIS TRANSLATES TO SURFACE TEMPERATURES
REACHING INTO THE 90'S AND POSSIBLY LOW HUNDREDS FOR THE NEBRASKA
PANHANDLE.
LONG TERM /FRIDAY THROUGH TUESDAY/
ISSUED AT 334 AM MDT WED AUG 6 2025
FRIDAY AND BEYOND WILL BRING A MORE ACTIVE WEATHER
PATTERN FOR THE INTERMOUNTAIN WEST. AN UPPER LEVEL LOW WILL PUSH
INTO THE ROCKY MOUNTAIN REGION FLATTENING OUR BROAD RIDGING PATTERN.
THIS FLATTENING WILL INCREASE WINDS FROM OUR CALM STEADY STATE TO A
MORE BREEZY STATE. THERE IS SOME MOISTURE RETURN WITH THE PASSAGE OF
THIS SYSTEM ENDING OUR RED FLAG WARNING AS RH VALUES RETURN ABOVE 15
PERCENT DESPITE FUELS REMAINING IN CRITICAL STATE. THIS MOISTURE
RETURN ALSO WOULD GIVE US DAILY THUNDERSTORM CHANCES AS THE
INTERMOUNTAIN WEST TRANSITIONS TO NORTHWEST FLOW. ANY DISTURBANCE
WOULD BE ABLE TO TAP INTO THIS MOISTURE POOL AND DEVELOP SHOWERS AND
THUNDERSTORMS AS IT LIFTS THE MOISTURE ALONG ITS PASSING.
TEMPERATURES ARE ALSO EXPECTED TO COOL BACK DOWN INTO THE 70'S AND
80'S AS COOLER AIR IS ADVECTED DOWN FROM THE CANADIAN PROVIDENCES
BEHIND THIS SYSTEM.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1137 PM MDT TUE AUG 5 2025
WYOMING TAFS...CLEAR SKIES WILL PREVAIL. WINDS WILL GUST TO
AND TO 25 KNOTS AFTER 16Z.
NEBRASKA TAFS...CLEAR SKIES WILL PREVAIL, EXCEPT FOR CEILINGS
NEAR 1500 FEET AT CHADRON AND ALLIANCE FROM 09Z TO 14Z. WINDS
WILL REMAIN 11 KNOTS OR LESS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING FROM NOON TO 8 PM MDT THURSDAY FOR WYZ417-418.
RED FLAG WARNING UNTIL 6 PM MDT FRIDAY FOR WYZ419>429.
NE...NONE.
SHORT TERM...MM
LONG TERM...MM
AVIATION...RUBIN
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