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000
FXUS65 KCYS 301005
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
405 AM MDT TUE SEP 30 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MDT TUE SEP 30 2014

LOW PRESSURE SYSTEM CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE
WILL CONTINUE ITS TRACK NORTHEAST INTO THE PLAINS THE REST OF THIS
MORNING. MOST RAIN SHOWER ACTIVITY WILL BE OVER THE NORTHERN
NEBRASKA PANHANDLE AND EAST CENTRAL WYOMING. GENERALLY A QUARTER
TO HALF INCH OF ADDITIONAL RAINFALL CAN BE EXPECTED THROUGH MID
MORNING AS THE RAIN SHIELD LIFTS NORTHEASTWARD ALONG WITH THE
LOW. COULD SEE ADDITIONAL RAIN SHOWERS DEVELOP IN THE WESTERN CWA
THIS AFTERNOON AND COOL AIR ALOFT AND MORNING SUNSHINE
DESTABILIZES THE BOUNDARY LAYER. NOT EXPECTING MUCH IN THE WAY OF
MEASURABLE PRECIPITATION THIS AFTEROON WITH MAINLY ISOLATED
SHOWERS. CAN NOT RULE OUT A FEW LIGHTNING STRIKES BUT GENERALLY
LOOKING FOR SHOWERS IF ANYTHING.

HIGH WIND WARNING REMAINS IN EFFECT FOR WIND PRONE AREAS OF
SOUTHEAST WYOMING. WINDS HAVE INCREASED OVER THE LAST SEVERAL
HOURS WITH A FEW SITES CLOSE TO HIGH WIND WARNING SPEEDS. LOOKING
MARGINAL AT BEST TO HIT HIGH WIND WARNING AT THIS POINT...BUT
CLOSE ENOUGH TO KEEP THE WARNING GOING FOR NOW. THE OTHER WIND
CONCERN IS INTO THE NORTHERN NEBRASKA PANHANDLE. 40 TO 50 KT WINDS
WILL BE IN PLACE NOT TOO FAR OFF THE SURFACE THIS MORNING. AS LOW
PRESSURE WRAPS UP SOME OF THESE WINDS WILL MAKE THEIR WAY TO THE
SURFACE SO ISSUED A WIND ADVISORY FOR THE NORTHERN PANHANDLE
THROUGH EARLY AFTERNOON. TOUGH CALL WITH SO MUCH CLOUD COVER
AROUND THIS MORNING BUT THEN AGAIN ALLIANCE REPORTED A WIND GUST
OVER 60 MPH AT 3 AM.

SHORTWAVE WILL DROP ACROSS THE AREA WEDNESDAY. THIS WAVE SHOULD
BRING SOME SHOWERS AND A FEW THUNDERSTORMS WEDNESDAY...AT LEAST
GIVEN THE EXPECTED TRACK. HIGHEST CHANCES FOR MEASUREABLE RAIN
LOOKS TO BE NEAR THE COLORADO BORDER. SKIES WILL CLEAR OUT FROM
WEST TO EAST WEDNESDAY NIGHT WITH SUNNY SKIES FOR THURSDAY UNDER
NORTHWEST FLOW ALOFT.

.LONG TERM...(THURSDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 315 AM MDT TUE SEP 30 2014

ALL LONG RANGE MODELS SHOW QUIET WEATHER FOR THE EXTENDED WITH NO
CONCERNS THROUGH NEXT WEEKEND. PERSISTENT DRY NORTHWESTERLY FLOW
WILL CONTINUE ACROSS THE AREA THROUGH THE PERIOD. JET STREAM WILL
RETREAT NORTHWARD TOWARDS THE CANADIAN BORDER WITH ONLY ONE WEAK
WAVE EXPECTED TO IMPACT THE AREA ON SUNDAY...WHICH WILL RESULT IN
THE POLAR JET STREAM DIGGING A LITTLE FURTHER SOUTH INTO THE
CENTRAL PLAINS...BRIEFLY. NO PRECIPITATION IS EXPECTED THROUGH THE
PERIOD WITH POP BELOW 10 PERCENT AND EVEN AROUND ZERO PERCENT FOR
SEVERAL DAYS. A SLOW WARMING TREND IS EXPECTED INTO THIS WEEKEND
WITH DAYTIME HIGHS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE
YEAR. HIGHS IN THE MID 60S TO MID 70S ARE EXPECTED ON
SATURDAY...WARMEST OVER THE HIGH PLAINS. TEMPERATURES WILL BE
SLIGHTLY COOLER ON SUNDAY AS A WEAK WAVE AND ASSOCIATED FRONT
ALOFT PUSH ACROSS THE AREA...BUT ABOVE AVERAGE TEMPS WILL CONTINUE
INTO EARLY NEXT WEEK. BREEZY CONDITIONS CAN BE EXPECTED ON MOST
DAYS...WHICH IS TYPICAL OF PROGRESSIVE NORTHWEST FLOW ALOFT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH TUESDAY NIGHT)
ISSUED AT 235 AM MDT TUE SEP 30 2014

STRONG SURFACE LOW PRESSURE WILL CONTINUE TO MOVE NORTHWARD THIS
MORNING...WITH THE CENTER OF THE LOW JUST PASSING THROUGH ALLIANCE
AT THIS HOUR. RAINFALL HAS SLOWLY DECREASED IN INTENSITY...WITH
MAINLY LIGHT TO MODERATE RAINFALL EXPECTED TO PERSIST NORTHEAST OF A
LINE EXTENDING FROM KDGW TO KSNY. BY SUNRISE...THIS AREA OF RAIN
IS EXPECTED TO BE NORTH OF KSNY AND KAIA WITH CONDITIONS IMPROVING
TO VFR. STRONG GUSTY WINDS ARE EXPECTED BEHIND THIS LOW AS IT
TRACKS NORTH OF THE AREA TODAY...WITH GUSTS UP TO 55 MPH POSSIBLE.
IFR CONDITIONS WILL GRADUALLY IMPROVE TO MVFR THIS MORNING ACROSS
WESTERN NEBRASKA...WITH VFR OVER SOUTHEAST WYOMING.

&&

.FIRE WEATHER...
ISSUED AT 404 AM MDT TUE SEP 30 2014

LOW PRESSURE WILL MOVE INTO THE NORTHERN PLAINS TODAY. WINDY
CONDITIONS WILL PREVAIL OVER FORECAST AREA AS THE PRESSURE
GRADIENT INCREASES THIS MORNING. RAIN SHOWERS WILL BE FOUND
OVER NORTHERN NEBRASKA PANHANDLE AND INTO EAST CENTRAL WYOMING
EARLY THIS MORNING BUT SHOWERS WILL MOVE TO THE NORTHEAST BY
THIS AFTERNOON. A FEW ISOLATED AFTERNOON SHOWERS POSSIBLE FOR
SOUTHEAST WYOMING THIS AFTERNOON. ANOTHER QUICK MOVING SYSTEM WILL
BRING SOME RAIN SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY.
OTHERWISE A DRY WEEK WITH WARMING TEMPERATURES THE LATTER HALF OF
THE WEEK.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL NOON MDT TODAY FOR WYZ106-110-116-117.

NE...WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR NEZ002-003-095-
     096.

&&

$$

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









000
FXUS65 KCYS 301005
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
405 AM MDT TUE SEP 30 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MDT TUE SEP 30 2014

LOW PRESSURE SYSTEM CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE
WILL CONTINUE ITS TRACK NORTHEAST INTO THE PLAINS THE REST OF THIS
MORNING. MOST RAIN SHOWER ACTIVITY WILL BE OVER THE NORTHERN
NEBRASKA PANHANDLE AND EAST CENTRAL WYOMING. GENERALLY A QUARTER
TO HALF INCH OF ADDITIONAL RAINFALL CAN BE EXPECTED THROUGH MID
MORNING AS THE RAIN SHIELD LIFTS NORTHEASTWARD ALONG WITH THE
LOW. COULD SEE ADDITIONAL RAIN SHOWERS DEVELOP IN THE WESTERN CWA
THIS AFTERNOON AND COOL AIR ALOFT AND MORNING SUNSHINE
DESTABILIZES THE BOUNDARY LAYER. NOT EXPECTING MUCH IN THE WAY OF
MEASURABLE PRECIPITATION THIS AFTEROON WITH MAINLY ISOLATED
SHOWERS. CAN NOT RULE OUT A FEW LIGHTNING STRIKES BUT GENERALLY
LOOKING FOR SHOWERS IF ANYTHING.

HIGH WIND WARNING REMAINS IN EFFECT FOR WIND PRONE AREAS OF
SOUTHEAST WYOMING. WINDS HAVE INCREASED OVER THE LAST SEVERAL
HOURS WITH A FEW SITES CLOSE TO HIGH WIND WARNING SPEEDS. LOOKING
MARGINAL AT BEST TO HIT HIGH WIND WARNING AT THIS POINT...BUT
CLOSE ENOUGH TO KEEP THE WARNING GOING FOR NOW. THE OTHER WIND
CONCERN IS INTO THE NORTHERN NEBRASKA PANHANDLE. 40 TO 50 KT WINDS
WILL BE IN PLACE NOT TOO FAR OFF THE SURFACE THIS MORNING. AS LOW
PRESSURE WRAPS UP SOME OF THESE WINDS WILL MAKE THEIR WAY TO THE
SURFACE SO ISSUED A WIND ADVISORY FOR THE NORTHERN PANHANDLE
THROUGH EARLY AFTERNOON. TOUGH CALL WITH SO MUCH CLOUD COVER
AROUND THIS MORNING BUT THEN AGAIN ALLIANCE REPORTED A WIND GUST
OVER 60 MPH AT 3 AM.

SHORTWAVE WILL DROP ACROSS THE AREA WEDNESDAY. THIS WAVE SHOULD
BRING SOME SHOWERS AND A FEW THUNDERSTORMS WEDNESDAY...AT LEAST
GIVEN THE EXPECTED TRACK. HIGHEST CHANCES FOR MEASUREABLE RAIN
LOOKS TO BE NEAR THE COLORADO BORDER. SKIES WILL CLEAR OUT FROM
WEST TO EAST WEDNESDAY NIGHT WITH SUNNY SKIES FOR THURSDAY UNDER
NORTHWEST FLOW ALOFT.

.LONG TERM...(THURSDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 315 AM MDT TUE SEP 30 2014

ALL LONG RANGE MODELS SHOW QUIET WEATHER FOR THE EXTENDED WITH NO
CONCERNS THROUGH NEXT WEEKEND. PERSISTENT DRY NORTHWESTERLY FLOW
WILL CONTINUE ACROSS THE AREA THROUGH THE PERIOD. JET STREAM WILL
RETREAT NORTHWARD TOWARDS THE CANADIAN BORDER WITH ONLY ONE WEAK
WAVE EXPECTED TO IMPACT THE AREA ON SUNDAY...WHICH WILL RESULT IN
THE POLAR JET STREAM DIGGING A LITTLE FURTHER SOUTH INTO THE
CENTRAL PLAINS...BRIEFLY. NO PRECIPITATION IS EXPECTED THROUGH THE
PERIOD WITH POP BELOW 10 PERCENT AND EVEN AROUND ZERO PERCENT FOR
SEVERAL DAYS. A SLOW WARMING TREND IS EXPECTED INTO THIS WEEKEND
WITH DAYTIME HIGHS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE
YEAR. HIGHS IN THE MID 60S TO MID 70S ARE EXPECTED ON
SATURDAY...WARMEST OVER THE HIGH PLAINS. TEMPERATURES WILL BE
SLIGHTLY COOLER ON SUNDAY AS A WEAK WAVE AND ASSOCIATED FRONT
ALOFT PUSH ACROSS THE AREA...BUT ABOVE AVERAGE TEMPS WILL CONTINUE
INTO EARLY NEXT WEEK. BREEZY CONDITIONS CAN BE EXPECTED ON MOST
DAYS...WHICH IS TYPICAL OF PROGRESSIVE NORTHWEST FLOW ALOFT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH TUESDAY NIGHT)
ISSUED AT 235 AM MDT TUE SEP 30 2014

STRONG SURFACE LOW PRESSURE WILL CONTINUE TO MOVE NORTHWARD THIS
MORNING...WITH THE CENTER OF THE LOW JUST PASSING THROUGH ALLIANCE
AT THIS HOUR. RAINFALL HAS SLOWLY DECREASED IN INTENSITY...WITH
MAINLY LIGHT TO MODERATE RAINFALL EXPECTED TO PERSIST NORTHEAST OF A
LINE EXTENDING FROM KDGW TO KSNY. BY SUNRISE...THIS AREA OF RAIN
IS EXPECTED TO BE NORTH OF KSNY AND KAIA WITH CONDITIONS IMPROVING
TO VFR. STRONG GUSTY WINDS ARE EXPECTED BEHIND THIS LOW AS IT
TRACKS NORTH OF THE AREA TODAY...WITH GUSTS UP TO 55 MPH POSSIBLE.
IFR CONDITIONS WILL GRADUALLY IMPROVE TO MVFR THIS MORNING ACROSS
WESTERN NEBRASKA...WITH VFR OVER SOUTHEAST WYOMING.

&&

.FIRE WEATHER...
ISSUED AT 404 AM MDT TUE SEP 30 2014

LOW PRESSURE WILL MOVE INTO THE NORTHERN PLAINS TODAY. WINDY
CONDITIONS WILL PREVAIL OVER FORECAST AREA AS THE PRESSURE
GRADIENT INCREASES THIS MORNING. RAIN SHOWERS WILL BE FOUND
OVER NORTHERN NEBRASKA PANHANDLE AND INTO EAST CENTRAL WYOMING
EARLY THIS MORNING BUT SHOWERS WILL MOVE TO THE NORTHEAST BY
THIS AFTERNOON. A FEW ISOLATED AFTERNOON SHOWERS POSSIBLE FOR
SOUTHEAST WYOMING THIS AFTERNOON. ANOTHER QUICK MOVING SYSTEM WILL
BRING SOME RAIN SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY.
OTHERWISE A DRY WEEK WITH WARMING TEMPERATURES THE LATTER HALF OF
THE WEEK.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL NOON MDT TODAY FOR WYZ106-110-116-117.

NE...WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR NEZ002-003-095-
     096.

&&

$$

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










000
FXUS65 KCYS 300558
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1156 PM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 955 PM MDT MON SEP 29 2014

IT WAS AN ACTIVE AFTERNOON AND EVENING ACROSS MUCH OF THE CWA
AS A INTENSE LOW PRESSURE SYSTEM MOVED ACROSS CENTRAL AND
NORTHERN COLORADO. A COLD FRONT SWEEPING OUT AHEAD OF THE LOW
INTO A MOIST AND UNSTABLE AIR MASS COMBINED WITH VERY STRONG
WINDS ALOFT PRODUCED STRONG TO SEVERE TSTORMS WITH LARGE HAIL
AND DAMAGING WINDS. PING PONG BALL SIZE HAIL WAS REPORTED WITH
A TSTORM SOUTH OF ALLIANCE EARLIER THIS EVENING. WITH THE SQUALL
LINE EAST OF OUR PANHANDLE COUNTIES...THE TORNADO WATCH WAS
ALLOWED TO EXPIRE AT 9 PM. ISOLATED TSTORMS WILL CONTINUE TONIGHT
EAST OF THE LARAMIE RANGE...WITH SOME HEAVIER RAIN SHOWERS FOR
WESTERN NEBRASKA PANHANDLE WHERE A FLOOD WATCH REMAINS IN EFFECT
FOR ANOTHER ONE TO TWO INCHES OF RAIN ATOP ONE TO THREE INCHES
THAT FELL LAST NIGHT AND THIS MORNING. AS THE SURFACE LOW DEEPENS
OVER WESTERN NEBRASKA LATE TONIGHT AND EARLY TUESDAY MORNING...
STRONG WEST WINDS WILL DEVELOP ACROSS MUCH OF SOUTHEAST WYOMING.
700MB WINDS PEAK AROUND 65 KT BETWEEN CHEYENNE AND RAWLINS AND
THE COLORADO BORDER AND WHEATLAND. A HIGH WIND WARNING REMAINS
IN EFFECT FROM MIDNIGHT TONIGHT THROUGH NOON TUESDAY. FINALLY...
ENOUGH COLD AIR BEHIND THIS SYSTEM TO LOWER SNOW LEVELS TO
8500 FT OVER THE SNOWY AND SIERRA MADRE RANGES TONIGHT AND
TUESDAY MORNING FOR LIGHT SNOW ACCUMULATIONS. UPDATED ZONES
ALREADY SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM MDT MON SEP 29 2014

CONVECTIVE LINE WAS ALREADY DEVELOPING THIS AFTERNOON EXTENDING
FROM ROCK RIVER SSE TOWARDS THE DENVER METRO AREA. ATMOSPHERIC
DESTABILIZATION ALBEIT WEAK HAS BEEN UNDERWAY BEHIND THE MORNING
CONVECTION AND AHEAD OF THIS SECONDARY CONVECTIVE LINE. ALTHOUGH
LINGERING CLOUD COVER HAS INHIBITED IT SOME. 21Z SFC ANALYSIS PLACED
THE 1003MB LOW SOUTH OF PUEBLO WITH PRESSURE FALLS TO THE NORTH
ALONG THE I25 CORRIDOR TOWARDS DENVER. LATEST SPC MESOANALYSIS SHOWED
1000 J/KG OF SBCAPE NOSING INTO THE SRN NEBRASKA PANHANDLE AS A BAND
OF 40-50 KNOTS OF DEEP LAYER SHEAR APPROACHED FROM THE SOUTHWEST.
INCREASINGLY FAVORABLE DEEP LAYER SHEAR WERE ASSOCIATED WITH A
POWERFUL LOW PRESSURE AREA THAT SATELLITE PIX SHOWED WAS LIFTING
NORTHEAST FROM THE FOUR CORNERS AREA. THIS FEATURE WILL LIFT INTO
COLORADO BY 6 PM BEFORE CLOSING OFF NR THE WY/NE STATE LINE BY
MIDNIGHT. THE AFOREMENTIONED SFC LOW NOW LOCATED NR PUEBLO WILL LIFT
NORTH INTO THE WRN NEBRASKA PANHANDLE THIS EVENING AND DEEPEN TO
993MB BY TUESDAY MORNING. AS IT DOES SO...LLVL SOUTHEAST FLOW
COMBINED WITH AN APPROACHING MID/UPPER-LEVEL SPEED MAX TO DRAW A
FAVORABLY SHEARED ENVIRONMENT...ESPECIALLY THROUGH THE EARLY THIS
EVENING. LATEST HRRR HAS DONE WELL WITH CONVECTIVE INITIATION SO FAR
AND SUGGESTS THE SEVERE POTENTIAL TO BE GREATEST WHILE STORM MODES
ARE DISCRETE...WITH EVEN A FEW ROTATING UPDRAFTS CONTAINING LARGE
HAIL...DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. THIS
WILL ESPECIALLY BE THE CASE FROM EASTERN LARAMIE COUNTY EAST TO
SIDNEY. BY EARLY/MID-EVENING SEVERE POTENTIAL WILL DROP OFF QUICKLY
AS CONVECTION BECOMES A MORE HOMOGENEOUS AREA OF MODERATE TO LOCALLY
HEAVY RAINFALL...WHICH WILL CONTINUE INTO TUESDAY MORNING. MANY OF
THESE AREAS OVR THE WRN NEBRASKA PANHANDLE RECEIVED 1-2 INCHES THIS
MORNING AND WITH ANOTHER AT LEAST 1-2 INCHES ON ITS WAY OVERNIGHT.
THE FLOOD WATCH FOR THE WRN NEBRASKA PANHANDLE WILL CONTINUE TO BE
WARRANTED TONIGHT. THE OTHER CONCERN ASSOCIATED WITH THIS DEEPENING
LOW PRESSURE AREA IS ITS IMPACT ON WINDS. SW/NE ORIENTED GRADIENTS
TIGHTEN SIGNIFICANTLY AFTER MIDNIGHT CONTINUING THRU TUESDAY
MORNING. ALTHOUGH A MARGINAL EVENT...THIS PUTS THE WIND PRONE AREAS
IN SE WYOMING UNDER THE GUN. EVEN THOUGH KCAG-KCPR GRADIENTS ARE A
BIT MARGINAL...H7 PROGS CONTINUE TO POINT TO THE POTENTIAL FOR A
HIGH WIND SET-UP EARLY TUESDAY. WILL KEEP THE HIGH WIND WARNING
GOING AS INHERITED.

WRAPAROUND MOISTURE WILL CONTINUE FOR A TIME NR THE PINE RIDGE
TUESDAY MORNING...BEFORE FINALLY LIFTING NORTHEAST BY MIDDAY. FLOW
WILL WESTERLY FOR TUESDAY...BUT THE CWFA WILL STILL BE INFLUENCED BY
THE LONGWAVE TROF OVER THE ROCKIES. A FEW SHOWERS AND ISOLATED
THUNDERSTORMS WILL STILL BE POSSIBLE...ESPECIALLY WEST OF THE
LARAMIE RANGE...ALTHOUGH COVERAGE WILL BE LESS.

THE NEXT FAST MOVING SHORTWAVE TROUGH WILL DIVE SOUTHEAST THRU THE
CWFA FOR WEDNESDAY. THIS WILL PROVIDE ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY OVR THE SOUTHEAST WYOMING MOUNTAINS AND
ADJACENT VALLEYS AND PLAINS. TEMPERATURES WILL WARM SLIGHTLY ON
TUESDAY...BACK INTO THE 60S MOST LOCATIONS WITH ANOTHER COOL DOWN
INTO THE 50S ANTICIPATED FOR WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 315 PM MDT MON SEP 29 2014

PRETTY QUIET EXTENDED PERIOD WITH PERSISTENT DRY NORTHWESTERLY FLOW
ALOFT IN PLACE.  SHORTWAVE WILL MOVE SOUTHEASTWARD FROM EASTERN
MONTANA INTO THE DAKOTAS DURING THE DAY ON THURS.  NO PRECIP IS
EXPECTED WITH THIS FEATURE AS IT WELL TO THE NORTHEAST. TEMPS WILL
BE SLIGHTLY BELOW NORMAL ON THURS WITH 700MB TEMPS AROUND 0C.  A
WARMING TREND WILL BEGIN ON FRI AND THEN CONTINUE INTO THE WEEKEND
WITH 700MB TEMPS RISING TO 5-10C.  ALTHOUGH THE STRONGEST FLOW ALOFT
IS OVER WESTERN SOUTH DAKOTA ON THURS THROUGH SUN...IT WILL STILL BE
BREEZY DURING THE AFTERNOONS ESPECIALLY ACROSS SOUTHEAST WY WITH
GOOD MIXING IN PLACE.  EXPECT WEST TO NORTHWEST WIND GUSTS TO 25-30
KT ON MOST AFTNS.  PRECIP CHANCES AND CLOUD COVER WILL BE VERY
LIMITED THROUGH THE PERIOD WITH GENERAL RIDGING OVER THE
INTERMOUNTAIN WEST AND A LACK OF MOISTURE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH TUESDAY AFTERNOON)

WIDESPREAD MODERATE TO HEAVY RAIN WITH EMBEDDED TSTMS WILL
CONTINUE ACROSS AREAS TO THE EAST OF THE LARAMIE RANGE THROUGH
TONIGHT. EXPECT PREVAILING IFR VIS IN THE RAIN. CDR WILL ALSO ALSO
SEE SOME LIFR CIGS THROUGH AROUND 03Z. THE RAIN WILL GRADUALLY BEGIN
TO TAPER OFF AFTER 03Z OVER SOUTHEAST WY AND AFTER 06Z IN THE
WESTERN NEBRASKA PANHANDLE. A COLD FRONT WILL PASS OVER THE AREA
LATER TONIGHT WITH WINDS BECOMING WESTERLY AND GUSTY. GUSTS TO 30-35
KT WILL BE COMMON THROUGH TUES AFTERNOON...ESPECIALLY ACROSS
SOUTHEAST WY.


&&

.FIRE WEATHER...
ISSUED AT 315 PM MDT MON SEP 29 2014

A STRONG AREA OF LOW PRESSURE WILL LIFT NORTHEAST FROM THE FOUR
CORNERS INTO THE DISTRICTS THROUGH TONIGHT. THIS SYSTEM WILL BE
BRING WIDESPREAD WETTING RAINS TO A LARGE PART OF THE
DISTRICT...ESPECIALLY EAST OF THE LARAMIE RANGE. SOME AREAS IN THE
WESTERN NEBRASKA PANHANDLE PICKED UP 1-2 INCHES OF RAIN THIS
MORNING AND ARE IN LINE FOR ANOTHER 1-2 INCHES...PERHAPS LOCALLY
HIGHER TONIGHT AND EARLY TUESDAY. A FLOOD WATCH HAS BEEN ISSUED
FOR THE WESTERN NEBRASKA PANHANDLE THROUGH NOON TUESDAY. WIND
PRONE AREAS WEST OF THE LARAMIE RANGE WILL BECOME VERY WINDY LATE
TONIGHT AND EARLY TUESDAY...WHERE A HIGH WIND WARNING IS IN
EFFECT. THE COOL AND UNSETTLED WEATHER WILL CONTINUE TUESDAY AND
WEDNESDAY...THOUGH COVERAGE AND INTENSITY WILL BE LIGHTER.
TEMPERATURES WILL BEGIN WARMING UP FOR THE END OF THE WEEK AND
UPCOMING WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL NOON MDT TUESDAY FOR WYZ106-110-116-117.

NE...FLOOD WATCH THROUGH TUESDAY MORNING FOR NEZ002-003-019>021-054-
     055-095-096.

&&

$$

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











000
FXUS65 KCYS 300558
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1156 PM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 955 PM MDT MON SEP 29 2014

IT WAS AN ACTIVE AFTERNOON AND EVENING ACROSS MUCH OF THE CWA
AS A INTENSE LOW PRESSURE SYSTEM MOVED ACROSS CENTRAL AND
NORTHERN COLORADO. A COLD FRONT SWEEPING OUT AHEAD OF THE LOW
INTO A MOIST AND UNSTABLE AIR MASS COMBINED WITH VERY STRONG
WINDS ALOFT PRODUCED STRONG TO SEVERE TSTORMS WITH LARGE HAIL
AND DAMAGING WINDS. PING PONG BALL SIZE HAIL WAS REPORTED WITH
A TSTORM SOUTH OF ALLIANCE EARLIER THIS EVENING. WITH THE SQUALL
LINE EAST OF OUR PANHANDLE COUNTIES...THE TORNADO WATCH WAS
ALLOWED TO EXPIRE AT 9 PM. ISOLATED TSTORMS WILL CONTINUE TONIGHT
EAST OF THE LARAMIE RANGE...WITH SOME HEAVIER RAIN SHOWERS FOR
WESTERN NEBRASKA PANHANDLE WHERE A FLOOD WATCH REMAINS IN EFFECT
FOR ANOTHER ONE TO TWO INCHES OF RAIN ATOP ONE TO THREE INCHES
THAT FELL LAST NIGHT AND THIS MORNING. AS THE SURFACE LOW DEEPENS
OVER WESTERN NEBRASKA LATE TONIGHT AND EARLY TUESDAY MORNING...
STRONG WEST WINDS WILL DEVELOP ACROSS MUCH OF SOUTHEAST WYOMING.
700MB WINDS PEAK AROUND 65 KT BETWEEN CHEYENNE AND RAWLINS AND
THE COLORADO BORDER AND WHEATLAND. A HIGH WIND WARNING REMAINS
IN EFFECT FROM MIDNIGHT TONIGHT THROUGH NOON TUESDAY. FINALLY...
ENOUGH COLD AIR BEHIND THIS SYSTEM TO LOWER SNOW LEVELS TO
8500 FT OVER THE SNOWY AND SIERRA MADRE RANGES TONIGHT AND
TUESDAY MORNING FOR LIGHT SNOW ACCUMULATIONS. UPDATED ZONES
ALREADY SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM MDT MON SEP 29 2014

CONVECTIVE LINE WAS ALREADY DEVELOPING THIS AFTERNOON EXTENDING
FROM ROCK RIVER SSE TOWARDS THE DENVER METRO AREA. ATMOSPHERIC
DESTABILIZATION ALBEIT WEAK HAS BEEN UNDERWAY BEHIND THE MORNING
CONVECTION AND AHEAD OF THIS SECONDARY CONVECTIVE LINE. ALTHOUGH
LINGERING CLOUD COVER HAS INHIBITED IT SOME. 21Z SFC ANALYSIS PLACED
THE 1003MB LOW SOUTH OF PUEBLO WITH PRESSURE FALLS TO THE NORTH
ALONG THE I25 CORRIDOR TOWARDS DENVER. LATEST SPC MESOANALYSIS SHOWED
1000 J/KG OF SBCAPE NOSING INTO THE SRN NEBRASKA PANHANDLE AS A BAND
OF 40-50 KNOTS OF DEEP LAYER SHEAR APPROACHED FROM THE SOUTHWEST.
INCREASINGLY FAVORABLE DEEP LAYER SHEAR WERE ASSOCIATED WITH A
POWERFUL LOW PRESSURE AREA THAT SATELLITE PIX SHOWED WAS LIFTING
NORTHEAST FROM THE FOUR CORNERS AREA. THIS FEATURE WILL LIFT INTO
COLORADO BY 6 PM BEFORE CLOSING OFF NR THE WY/NE STATE LINE BY
MIDNIGHT. THE AFOREMENTIONED SFC LOW NOW LOCATED NR PUEBLO WILL LIFT
NORTH INTO THE WRN NEBRASKA PANHANDLE THIS EVENING AND DEEPEN TO
993MB BY TUESDAY MORNING. AS IT DOES SO...LLVL SOUTHEAST FLOW
COMBINED WITH AN APPROACHING MID/UPPER-LEVEL SPEED MAX TO DRAW A
FAVORABLY SHEARED ENVIRONMENT...ESPECIALLY THROUGH THE EARLY THIS
EVENING. LATEST HRRR HAS DONE WELL WITH CONVECTIVE INITIATION SO FAR
AND SUGGESTS THE SEVERE POTENTIAL TO BE GREATEST WHILE STORM MODES
ARE DISCRETE...WITH EVEN A FEW ROTATING UPDRAFTS CONTAINING LARGE
HAIL...DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. THIS
WILL ESPECIALLY BE THE CASE FROM EASTERN LARAMIE COUNTY EAST TO
SIDNEY. BY EARLY/MID-EVENING SEVERE POTENTIAL WILL DROP OFF QUICKLY
AS CONVECTION BECOMES A MORE HOMOGENEOUS AREA OF MODERATE TO LOCALLY
HEAVY RAINFALL...WHICH WILL CONTINUE INTO TUESDAY MORNING. MANY OF
THESE AREAS OVR THE WRN NEBRASKA PANHANDLE RECEIVED 1-2 INCHES THIS
MORNING AND WITH ANOTHER AT LEAST 1-2 INCHES ON ITS WAY OVERNIGHT.
THE FLOOD WATCH FOR THE WRN NEBRASKA PANHANDLE WILL CONTINUE TO BE
WARRANTED TONIGHT. THE OTHER CONCERN ASSOCIATED WITH THIS DEEPENING
LOW PRESSURE AREA IS ITS IMPACT ON WINDS. SW/NE ORIENTED GRADIENTS
TIGHTEN SIGNIFICANTLY AFTER MIDNIGHT CONTINUING THRU TUESDAY
MORNING. ALTHOUGH A MARGINAL EVENT...THIS PUTS THE WIND PRONE AREAS
IN SE WYOMING UNDER THE GUN. EVEN THOUGH KCAG-KCPR GRADIENTS ARE A
BIT MARGINAL...H7 PROGS CONTINUE TO POINT TO THE POTENTIAL FOR A
HIGH WIND SET-UP EARLY TUESDAY. WILL KEEP THE HIGH WIND WARNING
GOING AS INHERITED.

WRAPAROUND MOISTURE WILL CONTINUE FOR A TIME NR THE PINE RIDGE
TUESDAY MORNING...BEFORE FINALLY LIFTING NORTHEAST BY MIDDAY. FLOW
WILL WESTERLY FOR TUESDAY...BUT THE CWFA WILL STILL BE INFLUENCED BY
THE LONGWAVE TROF OVER THE ROCKIES. A FEW SHOWERS AND ISOLATED
THUNDERSTORMS WILL STILL BE POSSIBLE...ESPECIALLY WEST OF THE
LARAMIE RANGE...ALTHOUGH COVERAGE WILL BE LESS.

THE NEXT FAST MOVING SHORTWAVE TROUGH WILL DIVE SOUTHEAST THRU THE
CWFA FOR WEDNESDAY. THIS WILL PROVIDE ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY OVR THE SOUTHEAST WYOMING MOUNTAINS AND
ADJACENT VALLEYS AND PLAINS. TEMPERATURES WILL WARM SLIGHTLY ON
TUESDAY...BACK INTO THE 60S MOST LOCATIONS WITH ANOTHER COOL DOWN
INTO THE 50S ANTICIPATED FOR WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 315 PM MDT MON SEP 29 2014

PRETTY QUIET EXTENDED PERIOD WITH PERSISTENT DRY NORTHWESTERLY FLOW
ALOFT IN PLACE.  SHORTWAVE WILL MOVE SOUTHEASTWARD FROM EASTERN
MONTANA INTO THE DAKOTAS DURING THE DAY ON THURS.  NO PRECIP IS
EXPECTED WITH THIS FEATURE AS IT WELL TO THE NORTHEAST. TEMPS WILL
BE SLIGHTLY BELOW NORMAL ON THURS WITH 700MB TEMPS AROUND 0C.  A
WARMING TREND WILL BEGIN ON FRI AND THEN CONTINUE INTO THE WEEKEND
WITH 700MB TEMPS RISING TO 5-10C.  ALTHOUGH THE STRONGEST FLOW ALOFT
IS OVER WESTERN SOUTH DAKOTA ON THURS THROUGH SUN...IT WILL STILL BE
BREEZY DURING THE AFTERNOONS ESPECIALLY ACROSS SOUTHEAST WY WITH
GOOD MIXING IN PLACE.  EXPECT WEST TO NORTHWEST WIND GUSTS TO 25-30
KT ON MOST AFTNS.  PRECIP CHANCES AND CLOUD COVER WILL BE VERY
LIMITED THROUGH THE PERIOD WITH GENERAL RIDGING OVER THE
INTERMOUNTAIN WEST AND A LACK OF MOISTURE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH TUESDAY AFTERNOON)

WIDESPREAD MODERATE TO HEAVY RAIN WITH EMBEDDED TSTMS WILL
CONTINUE ACROSS AREAS TO THE EAST OF THE LARAMIE RANGE THROUGH
TONIGHT. EXPECT PREVAILING IFR VIS IN THE RAIN. CDR WILL ALSO ALSO
SEE SOME LIFR CIGS THROUGH AROUND 03Z. THE RAIN WILL GRADUALLY BEGIN
TO TAPER OFF AFTER 03Z OVER SOUTHEAST WY AND AFTER 06Z IN THE
WESTERN NEBRASKA PANHANDLE. A COLD FRONT WILL PASS OVER THE AREA
LATER TONIGHT WITH WINDS BECOMING WESTERLY AND GUSTY. GUSTS TO 30-35
KT WILL BE COMMON THROUGH TUES AFTERNOON...ESPECIALLY ACROSS
SOUTHEAST WY.


&&

.FIRE WEATHER...
ISSUED AT 315 PM MDT MON SEP 29 2014

A STRONG AREA OF LOW PRESSURE WILL LIFT NORTHEAST FROM THE FOUR
CORNERS INTO THE DISTRICTS THROUGH TONIGHT. THIS SYSTEM WILL BE
BRING WIDESPREAD WETTING RAINS TO A LARGE PART OF THE
DISTRICT...ESPECIALLY EAST OF THE LARAMIE RANGE. SOME AREAS IN THE
WESTERN NEBRASKA PANHANDLE PICKED UP 1-2 INCHES OF RAIN THIS
MORNING AND ARE IN LINE FOR ANOTHER 1-2 INCHES...PERHAPS LOCALLY
HIGHER TONIGHT AND EARLY TUESDAY. A FLOOD WATCH HAS BEEN ISSUED
FOR THE WESTERN NEBRASKA PANHANDLE THROUGH NOON TUESDAY. WIND
PRONE AREAS WEST OF THE LARAMIE RANGE WILL BECOME VERY WINDY LATE
TONIGHT AND EARLY TUESDAY...WHERE A HIGH WIND WARNING IS IN
EFFECT. THE COOL AND UNSETTLED WEATHER WILL CONTINUE TUESDAY AND
WEDNESDAY...THOUGH COVERAGE AND INTENSITY WILL BE LIGHTER.
TEMPERATURES WILL BEGIN WARMING UP FOR THE END OF THE WEEK AND
UPCOMING WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL NOON MDT TUESDAY FOR WYZ106-110-116-117.

NE...FLOOD WATCH THROUGH TUESDAY MORNING FOR NEZ002-003-019>021-054-
     055-095-096.

&&

$$

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










000
FXUS65 KCYS 300356
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
956 PM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 955 PM MDT MON SEP 29 2014

IT WAS AN ACTIVE AFTERNOON AND EVENING ACROSS MUCH OF THE CWA
AS A INTENSE LOW PRESSURE SYSTEM MOVED ACROSS CENTRAL AND
NORTHERN COLORADO. A COLD FRONT SWEEPING OUT AHEAD OF THE LOW
INTO A MOIST AND UNSTABLE AIR MASS COMBINED WITH VERY STRONG
WINDS ALOFT PRODUCED STRONG TO SEVERE TSTORMS WITH LARGE HAIL
AND DAMAGING WINDS. PING PONG BALL SIZE HAIL WAS REPORTED WITH
A TSTORM SOUTH OF ALLIANCE EARLIER THIS EVENING. WITH THE SQUALL
LINE EAST OF OUR PANHANDLE COUNTIES...THE TORNADO WATCH WAS
ALLOWED TO EXPIRE AT 9 PM. ISOLATED TSTORMS WILL CONTINUE TONIGHT
EAST OF THE LARAMIE RANGE...WITH SOME HEAVIER RAIN SHOWERS FOR
WESTERN NEBRASKA PANHANDLE WHERE A FLOOD WATCH REMAINS IN EFFECT
FOR ANOTHER ONE TO TWO INCHES OF RAIN ATOP ONE TO THREE INCHES
THAT FELL LAST NIGHT AND THIS MORNING. AS THE SURFACE LOW DEEPENS
OVER WESTERN NEBRASKA LATE TONIGHT AND EARLY TUESDAY MORNING...
STRONG WEST WINDS WILL DEVELOP ACROSS MUCH OF SOUTHEAST WYOMING.
700MB WINDS PEAK AROUND 65 KT BETWEEN CHEYENNE AND RAWLINS AND
THE COLORADO BORDER AND WHEATLAND. A HIGH WIND WARNING REMAINS
IN EFFECT FROM MIDNIGHT TONIGHT THROUGH NOON TUESDAY. FINALLY...
ENOUGH COLD AIR BEHIND THIS SYSTEM TO LOWER SNOW LEVELS TO
8500 FT OVER THE SNOWY AND SIERRA MADRE RANGES TONIGHT AND
TUESDAY MORNING FOR LIGHT SNOW ACCUMULATIONS. UPDATED ZONES
ALREADY SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM MDT MON SEP 29 2014

CONVECTIVE LINE WAS ALREADY DEVELOPING THIS AFTERNOON EXTENDING
FROM ROCK RIVER SSE TOWARDS THE DENVER METRO AREA. ATMOSPHERIC
DESTABILIZATION ALBEIT WEAK HAS BEEN UNDERWAY BEHIND THE MORNING
CONVECTION AND AHEAD OF THIS SECONDARY CONVECTIVE LINE. ALTHOUGH
LINGERING CLOUD COVER HAS INHIBITED IT SOME. 21Z SFC ANALYSIS PLACED
THE 1003MB LOW SOUTH OF PUEBLO WITH PRESSURE FALLS TO THE NORTH
ALONG THE I25 CORRIDOR TOWARDS DENVER. LATEST SPC MESOANALYSIS SHOWED
1000 J/KG OF SBCAPE NOSING INTO THE SRN NEBRASKA PANHANDLE AS A BAND
OF 40-50 KNOTS OF DEEP LAYER SHEAR APPROACHED FROM THE SOUTHWEST.
INCREASINGLY FAVORABLE DEEP LAYER SHEAR WERE ASSOCIATED WITH A
POWERFUL LOW PRESSURE AREA THAT SATELLITE PIX SHOWED WAS LIFTING
NORTHEAST FROM THE FOUR CORNERS AREA. THIS FEATURE WILL LIFT INTO
COLORADO BY 6 PM BEFORE CLOSING OFF NR THE WY/NE STATE LINE BY
MIDNIGHT. THE AFOREMENTIONED SFC LOW NOW LOCATED NR PUEBLO WILL LIFT
NORTH INTO THE WRN NEBRASKA PANHANDLE THIS EVENING AND DEEPEN TO
993MB BY TUESDAY MORNING. AS IT DOES SO...LLVL SOUTHEAST FLOW
COMBINED WITH AN APPROACHING MID/UPPER-LEVEL SPEED MAX TO DRAW A
FAVORABLY SHEARED ENVIRONMENT...ESPECIALLY THROUGH THE EARLY THIS
EVENING. LATEST HRRR HAS DONE WELL WITH CONVECTIVE INITIATION SO FAR
AND SUGGESTS THE SEVERE POTENTIAL TO BE GREATEST WHILE STORM MODES
ARE DISCRETE...WITH EVEN A FEW ROTATING UPDRAFTS CONTAINING LARGE
HAIL...DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. THIS
WILL ESPECIALLY BE THE CASE FROM EASTERN LARAMIE COUNTY EAST TO
SIDNEY. BY EARLY/MID-EVENING SEVERE POTENTIAL WILL DROP OFF QUICKLY
AS CONVECTION BECOMES A MORE HOMOGENEOUS AREA OF MODERATE TO LOCALLY
HEAVY RAINFALL...WHICH WILL CONTINUE INTO TUESDAY MORNING. MANY OF
THESE AREAS OVR THE WRN NEBRASKA PANHANDLE RECEIVED 1-2 INCHES THIS
MORNING AND WITH ANOTHER AT LEAST 1-2 INCHES ON ITS WAY OVERNIGHT.
THE FLOOD WATCH FOR THE WRN NEBRASKA PANHANDLE WILL CONTINUE TO BE
WARRANTED TONIGHT. THE OTHER CONCERN ASSOCIATED WITH THIS DEEPENING
LOW PRESSURE AREA IS ITS IMPACT ON WINDS. SW/NE ORIENTED GRADIENTS
TIGHTEN SIGNIFICANTLY AFTER MIDNIGHT CONTINUING THRU TUESDAY
MORNING. ALTHOUGH A MARGINAL EVENT...THIS PUTS THE WIND PRONE AREAS
IN SE WYOMING UNDER THE GUN. EVEN THOUGH KCAG-KCPR GRADIENTS ARE A
BIT MARGINAL...H7 PROGS CONTINUE TO POINT TO THE POTENTIAL FOR A
HIGH WIND SET-UP EARLY TUESDAY. WILL KEEP THE HIGH WIND WARNING
GOING AS INHERITED.

WRAPAROUND MOISTURE WILL CONTINUE FOR A TIME NR THE PINE RIDGE
TUESDAY MORNING...BEFORE FINALLY LIFTING NORTHEAST BY MIDDAY. FLOW
WILL WESTERLY FOR TUESDAY...BUT THE CWFA WILL STILL BE INFLUENCED BY
THE LONGWAVE TROF OVER THE ROCKIES. A FEW SHOWERS AND ISOLATED
THUNDERSTORMS WILL STILL BE POSSIBLE...ESPECIALLY WEST OF THE
LARAMIE RANGE...ALTHOUGH COVERAGE WILL BE LESS.

THE NEXT FAST MOVING SHORTWAVE TROUGH WILL DIVE SOUTHEAST THRU THE
CWFA FOR WEDNESDAY. THIS WILL PROVIDE ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY OVR THE SOUTHEAST WYOMING MOUNTAINS AND
ADJACENT VALLEYS AND PLAINS. TEMPERATURES WILL WARM SLIGHTLY ON
TUESDAY...BACK INTO THE 60S MOST LOCATIONS WITH ANOTHER COOL DOWN
INTO THE 50S ANTICIPATED FOR WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 315 PM MDT MON SEP 29 2014

PRETTY QUIET EXTENDED PERIOD WITH PERSISTENT DRY NORTHWESTERLY FLOW
ALOFT IN PLACE.  SHORTWAVE WILL MOVE SOUTHEASTWARD FROM EASTERN
MONTANA INTO THE DAKOTAS DURING THE DAY ON THURS.  NO PRECIP IS
EXPECTED WITH THIS FEATURE AS IT WELL TO THE NORTHEAST. TEMPS WILL
BE SLIGHTLY BELOW NORMAL ON THURS WITH 700MB TEMPS AROUND 0C.  A
WARMING TREND WILL BEGIN ON FRI AND THEN CONTINUE INTO THE WEEKEND
WITH 700MB TEMPS RISING TO 5-10C.  ALTHOUGH THE STRONGEST FLOW ALOFT
IS OVER WESTERN SOUTH DAKOTA ON THURS THROUGH SUN...IT WILL STILL BE
BREEZY DURING THE AFTERNOONS ESPECIALLY ACROSS SOUTHEAST WY WITH
GOOD MIXING IN PLACE.  EXPECT WEST TO NORTHWEST WIND GUSTS TO 25-30
KT ON MOST AFTNS.  PRECIP CHANCES AND CLOUD COVER WILL BE VERY
LIMITED THROUGH THE PERIOD WITH GENERAL RIDGING OVER THE
INTERMOUNTAIN WEST AND A LACK OF MOISTURE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 556 PM MDT MON SEP 29 2014

WIDESPREAD MODERATE TO HEAVY RAIN WITH EMBEDDED TSTMS WILL
CONTINUE ACROSS AREAS TO THE EAST OF THE LARAMIE RANGE THROUGH
EARLY TONIGHT. EXPECT PREVAILING IFR VIS IN THE RAIN. CDR WILL
ALSO ALSO SEE SOME LIFR CIGS THROUGH AROUND 03Z. THE RAIN WILL
GRADUALLY BEGIN TO TAPER OFF AFTER 03Z OVER SOUTHEAST WY AND AFTER
06Z IN THE WESTERN NEBRASKA PANHANDLE. A COLD FRONT WILL PASS OVER
THE AREA LATER TONIGHT WITH WINDS BECOMING WESTERLY AND GUSTY.
GUSTS TO 30-35 KT WILL BE COMMON THROUGH TUES
AFTERNOON...ESPECIALLY ACROSS SOUTHEAST WY.


&&

.FIRE WEATHER...
ISSUED AT 315 PM MDT MON SEP 29 2014

A STRONG AREA OF LOW PRESSURE WILL LIFT NORTHEAST FROM THE FOUR
CORNERS INTO THE DISTRICTS THROUGH TONIGHT. THIS SYSTEM WILL BE
BRING WIDESPREAD WETTING RAINS TO A LARGE PART OF THE
DISTRICT...ESPECIALLY EAST OF THE LARAMIE RANGE. SOME AREAS IN THE
WESTERN NEBRASKA PANHANDLE PICKED UP 1-2 INCHES OF RAIN THIS
MORNING AND ARE IN LINE FOR ANOTHER 1-2 INCHES...PERHAPS LOCALLY
HIGHER TONIGHT AND EARLY TUESDAY. A FLOOD WATCH HAS BEEN ISSUED
FOR THE WESTERN NEBRASKA PANHANDLE THROUGH NOON TUESDAY. WIND
PRONE AREAS WEST OF THE LARAMIE RANGE WILL BECOME VERY WINDY LATE
TONIGHT AND EARLY TUESDAY...WHERE A HIGH WIND WARNING IS IN
EFFECT. THE COOL AND UNSETTLED WEATHER WILL CONTINUE TUESDAY AND
WEDNESDAY...THOUGH COVERAGE AND INTENSITY WILL BE LIGHTER.
TEMPERATURES WILL BEGIN WARMING UP FOR THE END OF THE WEEK AND
UPCOMING WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL NOON MDT TUESDAY FOR WYZ106-110-116-117.

NE...FLOOD WATCH THROUGH TUESDAY MORNING FOR NEZ002-003-019>021-054-
     055-095-096.

&&

$$

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








000
FXUS65 KCYS 300356
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
956 PM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 955 PM MDT MON SEP 29 2014

IT WAS AN ACTIVE AFTERNOON AND EVENING ACROSS MUCH OF THE CWA
AS A INTENSE LOW PRESSURE SYSTEM MOVED ACROSS CENTRAL AND
NORTHERN COLORADO. A COLD FRONT SWEEPING OUT AHEAD OF THE LOW
INTO A MOIST AND UNSTABLE AIR MASS COMBINED WITH VERY STRONG
WINDS ALOFT PRODUCED STRONG TO SEVERE TSTORMS WITH LARGE HAIL
AND DAMAGING WINDS. PING PONG BALL SIZE HAIL WAS REPORTED WITH
A TSTORM SOUTH OF ALLIANCE EARLIER THIS EVENING. WITH THE SQUALL
LINE EAST OF OUR PANHANDLE COUNTIES...THE TORNADO WATCH WAS
ALLOWED TO EXPIRE AT 9 PM. ISOLATED TSTORMS WILL CONTINUE TONIGHT
EAST OF THE LARAMIE RANGE...WITH SOME HEAVIER RAIN SHOWERS FOR
WESTERN NEBRASKA PANHANDLE WHERE A FLOOD WATCH REMAINS IN EFFECT
FOR ANOTHER ONE TO TWO INCHES OF RAIN ATOP ONE TO THREE INCHES
THAT FELL LAST NIGHT AND THIS MORNING. AS THE SURFACE LOW DEEPENS
OVER WESTERN NEBRASKA LATE TONIGHT AND EARLY TUESDAY MORNING...
STRONG WEST WINDS WILL DEVELOP ACROSS MUCH OF SOUTHEAST WYOMING.
700MB WINDS PEAK AROUND 65 KT BETWEEN CHEYENNE AND RAWLINS AND
THE COLORADO BORDER AND WHEATLAND. A HIGH WIND WARNING REMAINS
IN EFFECT FROM MIDNIGHT TONIGHT THROUGH NOON TUESDAY. FINALLY...
ENOUGH COLD AIR BEHIND THIS SYSTEM TO LOWER SNOW LEVELS TO
8500 FT OVER THE SNOWY AND SIERRA MADRE RANGES TONIGHT AND
TUESDAY MORNING FOR LIGHT SNOW ACCUMULATIONS. UPDATED ZONES
ALREADY SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM MDT MON SEP 29 2014

CONVECTIVE LINE WAS ALREADY DEVELOPING THIS AFTERNOON EXTENDING
FROM ROCK RIVER SSE TOWARDS THE DENVER METRO AREA. ATMOSPHERIC
DESTABILIZATION ALBEIT WEAK HAS BEEN UNDERWAY BEHIND THE MORNING
CONVECTION AND AHEAD OF THIS SECONDARY CONVECTIVE LINE. ALTHOUGH
LINGERING CLOUD COVER HAS INHIBITED IT SOME. 21Z SFC ANALYSIS PLACED
THE 1003MB LOW SOUTH OF PUEBLO WITH PRESSURE FALLS TO THE NORTH
ALONG THE I25 CORRIDOR TOWARDS DENVER. LATEST SPC MESOANALYSIS SHOWED
1000 J/KG OF SBCAPE NOSING INTO THE SRN NEBRASKA PANHANDLE AS A BAND
OF 40-50 KNOTS OF DEEP LAYER SHEAR APPROACHED FROM THE SOUTHWEST.
INCREASINGLY FAVORABLE DEEP LAYER SHEAR WERE ASSOCIATED WITH A
POWERFUL LOW PRESSURE AREA THAT SATELLITE PIX SHOWED WAS LIFTING
NORTHEAST FROM THE FOUR CORNERS AREA. THIS FEATURE WILL LIFT INTO
COLORADO BY 6 PM BEFORE CLOSING OFF NR THE WY/NE STATE LINE BY
MIDNIGHT. THE AFOREMENTIONED SFC LOW NOW LOCATED NR PUEBLO WILL LIFT
NORTH INTO THE WRN NEBRASKA PANHANDLE THIS EVENING AND DEEPEN TO
993MB BY TUESDAY MORNING. AS IT DOES SO...LLVL SOUTHEAST FLOW
COMBINED WITH AN APPROACHING MID/UPPER-LEVEL SPEED MAX TO DRAW A
FAVORABLY SHEARED ENVIRONMENT...ESPECIALLY THROUGH THE EARLY THIS
EVENING. LATEST HRRR HAS DONE WELL WITH CONVECTIVE INITIATION SO FAR
AND SUGGESTS THE SEVERE POTENTIAL TO BE GREATEST WHILE STORM MODES
ARE DISCRETE...WITH EVEN A FEW ROTATING UPDRAFTS CONTAINING LARGE
HAIL...DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. THIS
WILL ESPECIALLY BE THE CASE FROM EASTERN LARAMIE COUNTY EAST TO
SIDNEY. BY EARLY/MID-EVENING SEVERE POTENTIAL WILL DROP OFF QUICKLY
AS CONVECTION BECOMES A MORE HOMOGENEOUS AREA OF MODERATE TO LOCALLY
HEAVY RAINFALL...WHICH WILL CONTINUE INTO TUESDAY MORNING. MANY OF
THESE AREAS OVR THE WRN NEBRASKA PANHANDLE RECEIVED 1-2 INCHES THIS
MORNING AND WITH ANOTHER AT LEAST 1-2 INCHES ON ITS WAY OVERNIGHT.
THE FLOOD WATCH FOR THE WRN NEBRASKA PANHANDLE WILL CONTINUE TO BE
WARRANTED TONIGHT. THE OTHER CONCERN ASSOCIATED WITH THIS DEEPENING
LOW PRESSURE AREA IS ITS IMPACT ON WINDS. SW/NE ORIENTED GRADIENTS
TIGHTEN SIGNIFICANTLY AFTER MIDNIGHT CONTINUING THRU TUESDAY
MORNING. ALTHOUGH A MARGINAL EVENT...THIS PUTS THE WIND PRONE AREAS
IN SE WYOMING UNDER THE GUN. EVEN THOUGH KCAG-KCPR GRADIENTS ARE A
BIT MARGINAL...H7 PROGS CONTINUE TO POINT TO THE POTENTIAL FOR A
HIGH WIND SET-UP EARLY TUESDAY. WILL KEEP THE HIGH WIND WARNING
GOING AS INHERITED.

WRAPAROUND MOISTURE WILL CONTINUE FOR A TIME NR THE PINE RIDGE
TUESDAY MORNING...BEFORE FINALLY LIFTING NORTHEAST BY MIDDAY. FLOW
WILL WESTERLY FOR TUESDAY...BUT THE CWFA WILL STILL BE INFLUENCED BY
THE LONGWAVE TROF OVER THE ROCKIES. A FEW SHOWERS AND ISOLATED
THUNDERSTORMS WILL STILL BE POSSIBLE...ESPECIALLY WEST OF THE
LARAMIE RANGE...ALTHOUGH COVERAGE WILL BE LESS.

THE NEXT FAST MOVING SHORTWAVE TROUGH WILL DIVE SOUTHEAST THRU THE
CWFA FOR WEDNESDAY. THIS WILL PROVIDE ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY OVR THE SOUTHEAST WYOMING MOUNTAINS AND
ADJACENT VALLEYS AND PLAINS. TEMPERATURES WILL WARM SLIGHTLY ON
TUESDAY...BACK INTO THE 60S MOST LOCATIONS WITH ANOTHER COOL DOWN
INTO THE 50S ANTICIPATED FOR WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 315 PM MDT MON SEP 29 2014

PRETTY QUIET EXTENDED PERIOD WITH PERSISTENT DRY NORTHWESTERLY FLOW
ALOFT IN PLACE.  SHORTWAVE WILL MOVE SOUTHEASTWARD FROM EASTERN
MONTANA INTO THE DAKOTAS DURING THE DAY ON THURS.  NO PRECIP IS
EXPECTED WITH THIS FEATURE AS IT WELL TO THE NORTHEAST. TEMPS WILL
BE SLIGHTLY BELOW NORMAL ON THURS WITH 700MB TEMPS AROUND 0C.  A
WARMING TREND WILL BEGIN ON FRI AND THEN CONTINUE INTO THE WEEKEND
WITH 700MB TEMPS RISING TO 5-10C.  ALTHOUGH THE STRONGEST FLOW ALOFT
IS OVER WESTERN SOUTH DAKOTA ON THURS THROUGH SUN...IT WILL STILL BE
BREEZY DURING THE AFTERNOONS ESPECIALLY ACROSS SOUTHEAST WY WITH
GOOD MIXING IN PLACE.  EXPECT WEST TO NORTHWEST WIND GUSTS TO 25-30
KT ON MOST AFTNS.  PRECIP CHANCES AND CLOUD COVER WILL BE VERY
LIMITED THROUGH THE PERIOD WITH GENERAL RIDGING OVER THE
INTERMOUNTAIN WEST AND A LACK OF MOISTURE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 556 PM MDT MON SEP 29 2014

WIDESPREAD MODERATE TO HEAVY RAIN WITH EMBEDDED TSTMS WILL
CONTINUE ACROSS AREAS TO THE EAST OF THE LARAMIE RANGE THROUGH
EARLY TONIGHT. EXPECT PREVAILING IFR VIS IN THE RAIN. CDR WILL
ALSO ALSO SEE SOME LIFR CIGS THROUGH AROUND 03Z. THE RAIN WILL
GRADUALLY BEGIN TO TAPER OFF AFTER 03Z OVER SOUTHEAST WY AND AFTER
06Z IN THE WESTERN NEBRASKA PANHANDLE. A COLD FRONT WILL PASS OVER
THE AREA LATER TONIGHT WITH WINDS BECOMING WESTERLY AND GUSTY.
GUSTS TO 30-35 KT WILL BE COMMON THROUGH TUES
AFTERNOON...ESPECIALLY ACROSS SOUTHEAST WY.


&&

.FIRE WEATHER...
ISSUED AT 315 PM MDT MON SEP 29 2014

A STRONG AREA OF LOW PRESSURE WILL LIFT NORTHEAST FROM THE FOUR
CORNERS INTO THE DISTRICTS THROUGH TONIGHT. THIS SYSTEM WILL BE
BRING WIDESPREAD WETTING RAINS TO A LARGE PART OF THE
DISTRICT...ESPECIALLY EAST OF THE LARAMIE RANGE. SOME AREAS IN THE
WESTERN NEBRASKA PANHANDLE PICKED UP 1-2 INCHES OF RAIN THIS
MORNING AND ARE IN LINE FOR ANOTHER 1-2 INCHES...PERHAPS LOCALLY
HIGHER TONIGHT AND EARLY TUESDAY. A FLOOD WATCH HAS BEEN ISSUED
FOR THE WESTERN NEBRASKA PANHANDLE THROUGH NOON TUESDAY. WIND
PRONE AREAS WEST OF THE LARAMIE RANGE WILL BECOME VERY WINDY LATE
TONIGHT AND EARLY TUESDAY...WHERE A HIGH WIND WARNING IS IN
EFFECT. THE COOL AND UNSETTLED WEATHER WILL CONTINUE TUESDAY AND
WEDNESDAY...THOUGH COVERAGE AND INTENSITY WILL BE LIGHTER.
TEMPERATURES WILL BEGIN WARMING UP FOR THE END OF THE WEEK AND
UPCOMING WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL NOON MDT TUESDAY FOR WYZ106-110-116-117.

NE...FLOOD WATCH THROUGH TUESDAY MORNING FOR NEZ002-003-019>021-054-
     055-095-096.

&&

$$

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







000
FXUS65 KCYS 300007
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
607 PM MDT MON SEP 29 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM MDT MON SEP 29 2014

CONVECTIVE LINE WAS ALREADY DEVELOPING THIS AFTERNOON EXTENDING
FROM ROCK RIVER SSE TOWARDS THE DENVER METRO AREA. ATMOSPHERIC
DESTABILIZATION ALBEIT WEAK HAS BEEN UNDERWAY BEHIND THE MORNING
CONVECTION AND AHEAD OF THIS SECONDARY CONVECTIVE LINE. ALTHOUGH
LINGERING CLOUD COVER HAS INHIBITED IT SOME. 21Z SFC ANALYSIS PLACED
THE 1003MB LOW SOUTH OF PUEBLO WITH PRESSURE FALLS TO THE NORTH
ALONG THE I25 CORRIDOR TOWARDS DENVER. LATEST SPC MESOANALYSIS SHOWED
1000 J/KG OF SBCAPE NOSING INTO THE SRN NEBRASKA PANHANDLE AS A BAND
OF 40-50 KNOTS OF DEEP LAYER SHEAR APPROACHED FROM THE SOUTHWEST.
INCREASINGLY FAVORABLE DEEP LAYER SHEAR WERE ASSOCIATED WITH A
POWERFUL LOW PRESSURE AREA THAT SATELLITE PIX SHOWED WAS LIFTING
NORTHEAST FROM THE FOUR CORNERS AREA. THIS FTR WILL LIFT INTO
COLORADO BY 6 PM BEFORE CLOSING OFF NR THE WY/NE STATELINE BY
MIDNIGHT. THE AFOREMENTIONED SFC LOW NOW LOCATED NR PUEBLO WILL LIFT
NORTH INTO THE WRN NEBRASKA PANHANDLE THIS EVENING AND DEEPEN TO
993MB BY TUESDAY MORNING. AS IT DOES SO...LLVL SOUTHEAST FLOW
COMBINED WITH AN APPROACHING MID/UPPER-LEVEL SPEED MAX TO DRAW A
FAVORABLY SHEARED ENVIRONMENT...ESPECIALLY THROUGH THE EARLY THIS
EVENING. LATEST HRRR HAS DONE WELL WITH CONVECTIVE INITIATION SO FAR
AND SUGGESTS THE SEVERE POTENTIAL TO BE GREATEST WHILE STORM MODES
ARE DISCRETE...WITH EVEN A FEW ROTATING UPDRAFTS CONTAINING LARGE
HAIL...DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. THIS
WILL ESPECIALLY BE THE CASE FROM EASTERN LARAMIE COUNTY EAST TO
SIDNEY. BY EARLY/MID-EVENING SEVERE POTENTIAL WILL DROP OFF QUICKLY
AS CONVECTION BECOMES A MORE HOMOGENEOUS AREA OF MODERATE TO LOCALLY
HEAVY RAINFALL...WHICH WILL CONTINUE INTO TUESDAY MORNING. MANY OF
THESE AREAS OVR THE WRN NEBRASKA PANHANDLE RECEIVED 1-2 INCHES THIS
MORNING AND WITH ANOTHER AT LEAST 1-2 INCHES ON ITS WAY OVERNIGHT.
THE FLOOD WATCH FOR THE WRN NEBRASKA PANHANDLE WILL CONTINUE TO BE
WARRANTED TONIGHT. THE OTHER CONCERN ASSOCIATED WITH THIS DEEPENING
LOW PRESSURE AREA IS ITS IMPACT ON WINDS. SW/NE ORIENTED GRADIENTS
TIGHTEN SIGNIFICANTLY AFTER MIDNIGHT CONTINUING THRU TUESDAY
MORNING. ALTHOUGH A MARGINAL EVENT...THIS PUTS THE WIND PRONE AREAS
IN SE WYOMING UNDER THE GUN. EVEN THOUGH KCAG-KCPR GRADIENTS ARE A
BIT MARGINAL...H7 PROGS CONTINUE TO POINT TO THE POTENTIAL FOR A
HIGH WIND SET-UP EARLY TUESDAY. WILL KEEP THE HIGH WIND WARNING
GOING AS INHERITED.

WRAPAROUND MOISTURE WILL CONTINUE FOR A TIME NR THE PINE RIDGE
TUESDAY MORNING...BEFORE FINALLY LIFTING NORTHEAST BY MIDDAY. FLOW
WILL WESTERLY FOR TUESDAY...BUT THE CWFA WILL STILL BE INFLUENCED BY
THE LONGWAVE TROF OVER THE ROCKIES. A FEW SHOWERS AND ISOLATED
THUNDERSTORMS WILL STILL BE POSSIBLE...ESPECIALLY WEST OF THE
LARAMIE RANGE...ALTHOUGH COVERAGE WILL BE LESS.

THE NEXT FAST MOVING SHORTWAVE TROUGH WILL DIVE SOUTHEAST THRU THE
CWFA FOR WEDNESDAY. THIS WILL PROVIDE ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY OVR THE SOUTHEAST WYOMING MOUNTAINS AND
ADJACENT VALLEYS AND PLAINS. TEMPERATURES WILL WARM SLIGHTLY ON
TUESDAY...BACK INTO THE 60S MOST LOCATIONS WITH ANOTHER COOL DOWN
INTO THE 50S ANTICIPATED FOR WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 315 PM MDT MON SEP 29 2014

PRETTY QUIET EXTENDED PERIOD WITH PERSISTENT DRY NORTHWESTERLY FLOW
ALOFT IN PLACE.  SHORTWAVE WILL MOVE SOUTHEASTWARD FROM EASTERN
MONTANA INTO THE DAKOTAS DURING THE DAY ON THURS.  NO PRECIP IS
EXPECTED WITH THIS FEATURE AS IT WELL TO THE NORTHEAST. TEMPS WILL
BE SLIGHTLY BELOW NORMAL ON THURS WITH 700MB TEMPS AROUND 0C.  A
WARMING TREND WILL BEGIN ON FRI AND THEN CONTINUE INTO THE WEEKEND
WITH 700MB TEMPS RISING TO 5-10C.  ALTHOUGH THE STRONGEST FLOW ALOFT
IS OVER WESTERN SOUTH DAKOTA ON THURS THROUGH SUN...IT WILL STILL BE
BREEZY DURING THE AFTERNOONS ESPECIALLY ACROSS SOUTHEAST WY WITH
GOOD MIXING IN PLACE.  EXPECT WEST TO NORTHWEST WIND GUSTS TO 25-30
KTS ON MOST AFTNS.  PRECIP CHANCES AND CLOUD COVER WILL BE VERY
LIMITED THROUGH THE PERIOD WITH GENERAL RIDGING OVER THE
INTERMOUNTAIN WEST AND A LACK OF MOISTURE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 556 PM MDT MON SEP 29 2014

WIDESPREAD MODERATE TO HEAVY RAIN WITH EMBEDDED TSTMS WILL
CONTINUE ACROSS AREAS TO THE EAST OF THE LARAMIE RANGE THROUGH
EARLY TONIGHT. EXPECT PREVAILING IFR VIS IN THE RAIN. CDR WILL
ALSO ALSO SEE SOME LIFR CIGS THROUGH AROUND 03Z. THE RAIN WILL
GRADUALLY BEGIN TO TAPER OFF AFTER 03Z OVER SOUTHEAST WY AND AFTER
06Z IN THE WESTERN NEBRASKA PANHANDLE. A COLD FRONT WILL PASS OVER
THE AREA LATER TONIGHT WITH WINDS BECOMING WESTERLY AND GUSTY.
GUSTS TO 30-35 KTS WILL BE COMMON THROUGH TUES
AFTERNOON...ESPECIALLY ACROSS SOUTHEAST WY.

&&

.FIRE WEATHER...
ISSUED AT 315 PM MDT MON SEP 29 2014

A STRONG AREA OF LOW PRESSURE WILL LIFT NORTHEAST FROM THE FOUR
CORNERS INTO THE DISTRICTS THROUGH TONIGHT. THIS SYSTEM WILL BE
BRING WIDESPREAD WETTING RAINS TO A LARGE PART OF THE
DISTRICT...ESPECIALLY EAST OF THE LARAMIE RANGE. SOME AREAS IN THE
WESTERN NEBRASKA PANHANDLE PICKED UP 1-2 INCHES OF RAIN THIS
MORNING AND ARE IN LINE FOR ANOTHER 1-2 INCHES...PERHAPS LOCALLY
HIGHER TONIGHT AND EARLY TUESDAY. A FLOOD WATCH HAS BEEN ISSUED
FOR THE WESTERN NEBRASKA PANHANDLE THROUGH NOON TUESDAY. WIND
PRONE AREAS WEST OF THE LARAMIE RANGE WILL BECOME VERY WINDY LATE
TONIGHT AND EARLY TUESDAY...WHERE A HIGH WIND WARNING IS IN
EFFECT. THE COOL AND UNSETTLED WEATHER WILL CONTINUE TUESDAY AND
WEDNESDAY...THOUGH COVERAGE AND INTENSITY WILL BE LIGHTER.
TEMPERATURES WILL BEGIN WARMING UP FOR THE END OF THE WEEK AND
UPCOMING WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...FLOOD WATCH THROUGH TUESDAY MORNING FOR NEZ002-003-019>021-054-
     055-095-096.

&&

$$

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






000
FXUS65 KCYS 292117
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
317 PM MDT MON SEP 29 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM MDT MON SEP 29 2014

CONVECTIVE LINE WAS ALREADY DEVELOPING THIS AFTERNOON EXTENDING
FROM ROCK RIVER SSE TOWARDS THE DENVER METRO AREA. ATMOSPHERIC
DESTABILIZATION ALBEIT WEAK HAS BEEN UNDERWAY BEHIND THE MORNING
CONVECTION AND AHEAD OF THIS SECONDARY CONVECTIVE LINE. ALTHOUGH
LINGERING CLOUD COVER HAS INHIBITED IT SOME. 21Z SFC ANALYSIS PLACED
THE 1003MB LOW SOUTH OF PUEBLO WITH PRESSURE FALLS TO THE NORTH
ALONG THE I25 CORRIDOR TOWARDS DENVER. LATEST SPC MESOANALYSIS SHOWED
1000 J/KG OF SBCAPE NOSING INTO THE SRN NEBRASKA PANHANDLE AS A BAND
OF 40-50 KNOTS OF DEEP LAYER SHEAR APPROACHED FROM THE SOUTHWEST.
INCREASINGLY FAVORABLE DEEP LAYER SHEAR WERE ASSOCIATED WITH A
POWERFUL LOW PRESSURE AREA THAT SATELLITE PIX SHOWED WAS LIFTING
NORTHEAST FROM THE FOUR CORNERS AREA. THIS FTR WILL LIFT INTO
COLORADO BY 6 PM BEFORE CLOSING OFF NR THE WY/NE STATELINE BY
MIDNIGHT. THE AFOREMENTIONED SFC LOW NOW LOCATED NR PUEBLO WILL LIFT
NORTH INTO THE WRN NEBRASKA PANHANDLE THIS EVENING AND DEEPEN TO
993MB BY TUESDAY MORNING. AS IT DOES SO...LLVL SOUTHEAST FLOW
COMBINED WITH AN APPROACHING MID/UPPER-LEVEL SPEED MAX TO DRAW A
FAVORABLY SHEARED ENVIRONMENT...ESPECIALLY THROUGH THE EARLY THIS
EVENING. LATEST HRRR HAS DONE WELL WITH CONVECTIVE INITIATION SO FAR
AND SUGGESTS THE SEVERE POTENTIAL TO BE GREATEST WHILE STORM MODES
ARE DISCRETE...WITH EVEN A FEW ROTATING UPDRAFTS CONTAINING LARGE
HAIL...DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. THIS
WILL ESPECIALLY BE THE CASE FROM EASTERN LARAMIE COUNTY EAST TO
SIDNEY. BY EARLY/MID-EVENING SEVERE POTENTIAL WILL DROP OFF QUICKLY
AS CONVECTION BECOMES A MORE HOMOGENEOUS AREA OF MODERATE TO LOCALLY
HEAVY RAINFALL...WHICH WILL CONTINUE INTO TUESDAY MORNING. MANY OF
THESE AREAS OVR THE WRN NEBRASKA PANHANDLE RECEIVED 1-2 INCHES THIS
MORNING AND WITH ANOTHER AT LEAST 1-2 INCHES ON ITS WAY OVERNIGHT.
THE FLOOD WATCH FOR THE WRN NEBRASKA PANHANDLE WILL CONTINUE TO BE
WARRANTED TONIGHT. THE OTHER CONCERN ASSOCIATED WITH THIS DEEPENING
LOW PRESSURE AREA IS ITS IMPACT ON WINDS. SW/NE ORIENTED GRADIENTS
TIGHTEN SIGNIFICANTLY AFTER MIDNIGHT CONTINUING THRU TUESDAY
MORNING. ALTHOUGH A MARGINAL EVENT...THIS PUTS THE WIND PRONE AREAS
IN SE WYOMING UNDER THE GUN. EVEN THOUGH KCAG-KCPR GRADIENTS ARE A
BIT MARGINAL...H7 PROGS CONTINUE TO POINT TO THE POTENTIAL FOR A
HIGH WIND SET-UP EARLY TUESDAY. WILL KEEP THE HIGH WIND WARNING
GOING AS INHERITED.

WRAPAROUND MOISTURE WILL CONTINUE FOR A TIME NR THE PINE RIDGE
TUESDAY MORNING...BEFORE FINALLY LIFTING NORTHEAST BY MIDDAY. FLOW
WILL WESTERLY FOR TUESDAY...BUT THE CWFA WILL STILL BE INFLUENCED BY
THE LONGWAVE TROF OVER THE ROCKIES. A FEW SHOWERS AND ISOLATED
THUNDERSTORMS WILL STILL BE POSSIBLE...ESPECIALLY WEST OF THE
LARAMIE RANGE...ALTHOUGH COVERAGE WILL BE LESS.

THE NEXT FAST MOVING SHORTWAVE TROUGH WILL DIVE SOUTHEAST THRU THE
CWFA FOR WEDNESDAY. THIS WILL PROVIDE ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY OVR THE SOUTHEAST WYOMING MOUNTAINS AND
ADJACENT VALLEYS AND PLAINS. TEMPERATURES WILL WARM SLIGHTLY ON
TUESDAY...BACK INTO THE 60S MOST LOCATIONS WITH ANOTHER COOL DOWN
INTO THE 50S ANTICIPATED FOR WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 315 PM MDT MON SEP 29 2014

PRETTY QUIET EXTENDED PERIOD WITH PERSISTENT DRY NORTHWESTERLY FLOW
ALOFT IN PLACE.  SHORTWAVE WILL MOVE SOUTHEASTWARD FROM EASTERN
MONTANA INTO THE DAKOTAS DURING THE DAY ON THURS.  NO PRECIP IS
EXPECTED WITH THIS FEATURE AS IT WELL TO THE NORTHEAST. TEMPS WILL
BE SLIGHTLY BELOW NORMAL ON THURS WITH 700MB TEMPS AROUND 0C.  A
WARMING TREND WILL BEGIN ON FRI AND THEN CONTINUE INTO THE WEEKEND
WITH 700MB TEMPS RISING TO 5-10C.  ALTHOUGH THE STRONGEST FLOW ALOFT
IS OVER WESTERN SOUTH DAKOTA ON THURS THROUGH SUN...IT WILL STILL BE
BREEZY DURING THE AFTERNOONS ESPECIALLY ACROSS SOUTHEAST WY WITH
GOOD MIXING IN PLACE.  EXPECT WEST TO NORTHWEST WIND GUSTS TO 25-30
KTS ON MOST AFTNS.  PRECIP CHANCES AND CLOUD COVER WILL BE VERY
LIMITED THROUGH THE PERIOD WITH GENERAL RIDGING OVER THE
INTERMOUNTAIN WEST AND A LACK OF MOISTURE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1153 AM MDT MON SEP 29 2014

GOING TO GET A BREAK FROM THE RAIN AND LOWER CIGS THROUGH THE
EARLY AFTERNOON. WIDESPREAD MODERATE RAIN WITH EMBEDDED TSTMS IS
EXPECTED TO DEVELOP AT LAR AND CYS AROUND 21Z AND THEN SPREAD
NORTH AND EAST INTO THE NEBRASKA PANHANDLE DURING THE EARLY
EVENING. SINCE RAIN WILL LIKELY BE MODERATE TO HEAVY...WENT WITH
PREVAILING IFR CONDITIONS DURING THE EARLY EVENING OVER THE PLAINS
SITES. RAIN WILL LIKELY LINGER OVER THE NORTHERN PANHANDLE THROUGH
TUES MORNING. SOUTHEAST WINDS WILL BE GUSTY OVER THE PANHANDLE
THROUGH THE AFTN. A COLD FRONT WILL SWING ACROSS THE REGION AFTER
06Z WITH WINDS SWITCHING TO WEST AND SOUTHWEST. IT WILL BE WINDY
AFTER THE FRONTAL PASSAGE WITH GUSTS TO 30-35 KTS THROUGH THE
REMAINDER OF THE TAF PERIOD...ESPECIALLY OVER SOUTHEAST WY.


&&

.FIRE WEATHER...
ISSUED AT 315 PM MDT MON SEP 29 2014

A STRONG AREA OF LOW PRESSURE WILL LIFT NORTHEAST FROM THE FOUR
CORNERS INTO THE DISTRICTS THROUGH TONIGHT. THIS SYSTEM WILL BE
BRING WIDESPREAD WETTING RAINS TO A LARGE PART OF THE
DISTRICT...ESPECIALLY EAST OF THE LARAMIE RANGE. SOME AREAS IN THE
WESTERN NEBRASKA PANHANDLE PICKED UP 1-2 INCHES OF RAIN THIS
MORNING AND ARE IN LINE FOR ANOTHER 1-2 INCHES...PERHAPS LOCALLY
HIGHER TONIGHT AND EARLY TUESDAY. A FLOOD WATCH HAS BEEN ISSUED
FOR THE WESTERN NEBRASKA PANHANDLE THROUGH NOON TUESDAY. WIND
PRONE AREAS WEST OF THE LARAMIE RANGE WILL BECOME VERY WINDY LATE
TONIGHT AND EARLY TUESDAY...WHERE A HIGH WIND WARNING IS IN
EFFECT. THE COOL AND UNSETTLED WEATHER WILL CONTINUE TUESDAY AND
WEDNESDAY...THOUGH COVERAGE AND INTENSITY WILL BE LIGHTER.
TEMPERATURES WILL BEGIN WARMING UP FOR THE END OF THE WEEK AND
UPCOMING WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...FLOOD WATCH THROUGH TUESDAY MORNING FOR NEZ002-003-019>021-054-
     055-095-096.

&&

$$

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





000
FXUS65 KCYS 292117
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
317 PM MDT MON SEP 29 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM MDT MON SEP 29 2014

CONVECTIVE LINE WAS ALREADY DEVELOPING THIS AFTERNOON EXTENDING
FROM ROCK RIVER SSE TOWARDS THE DENVER METRO AREA. ATMOSPHERIC
DESTABILIZATION ALBEIT WEAK HAS BEEN UNDERWAY BEHIND THE MORNING
CONVECTION AND AHEAD OF THIS SECONDARY CONVECTIVE LINE. ALTHOUGH
LINGERING CLOUD COVER HAS INHIBITED IT SOME. 21Z SFC ANALYSIS PLACED
THE 1003MB LOW SOUTH OF PUEBLO WITH PRESSURE FALLS TO THE NORTH
ALONG THE I25 CORRIDOR TOWARDS DENVER. LATEST SPC MESOANALYSIS SHOWED
1000 J/KG OF SBCAPE NOSING INTO THE SRN NEBRASKA PANHANDLE AS A BAND
OF 40-50 KNOTS OF DEEP LAYER SHEAR APPROACHED FROM THE SOUTHWEST.
INCREASINGLY FAVORABLE DEEP LAYER SHEAR WERE ASSOCIATED WITH A
POWERFUL LOW PRESSURE AREA THAT SATELLITE PIX SHOWED WAS LIFTING
NORTHEAST FROM THE FOUR CORNERS AREA. THIS FTR WILL LIFT INTO
COLORADO BY 6 PM BEFORE CLOSING OFF NR THE WY/NE STATELINE BY
MIDNIGHT. THE AFOREMENTIONED SFC LOW NOW LOCATED NR PUEBLO WILL LIFT
NORTH INTO THE WRN NEBRASKA PANHANDLE THIS EVENING AND DEEPEN TO
993MB BY TUESDAY MORNING. AS IT DOES SO...LLVL SOUTHEAST FLOW
COMBINED WITH AN APPROACHING MID/UPPER-LEVEL SPEED MAX TO DRAW A
FAVORABLY SHEARED ENVIRONMENT...ESPECIALLY THROUGH THE EARLY THIS
EVENING. LATEST HRRR HAS DONE WELL WITH CONVECTIVE INITIATION SO FAR
AND SUGGESTS THE SEVERE POTENTIAL TO BE GREATEST WHILE STORM MODES
ARE DISCRETE...WITH EVEN A FEW ROTATING UPDRAFTS CONTAINING LARGE
HAIL...DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. THIS
WILL ESPECIALLY BE THE CASE FROM EASTERN LARAMIE COUNTY EAST TO
SIDNEY. BY EARLY/MID-EVENING SEVERE POTENTIAL WILL DROP OFF QUICKLY
AS CONVECTION BECOMES A MORE HOMOGENEOUS AREA OF MODERATE TO LOCALLY
HEAVY RAINFALL...WHICH WILL CONTINUE INTO TUESDAY MORNING. MANY OF
THESE AREAS OVR THE WRN NEBRASKA PANHANDLE RECEIVED 1-2 INCHES THIS
MORNING AND WITH ANOTHER AT LEAST 1-2 INCHES ON ITS WAY OVERNIGHT.
THE FLOOD WATCH FOR THE WRN NEBRASKA PANHANDLE WILL CONTINUE TO BE
WARRANTED TONIGHT. THE OTHER CONCERN ASSOCIATED WITH THIS DEEPENING
LOW PRESSURE AREA IS ITS IMPACT ON WINDS. SW/NE ORIENTED GRADIENTS
TIGHTEN SIGNIFICANTLY AFTER MIDNIGHT CONTINUING THRU TUESDAY
MORNING. ALTHOUGH A MARGINAL EVENT...THIS PUTS THE WIND PRONE AREAS
IN SE WYOMING UNDER THE GUN. EVEN THOUGH KCAG-KCPR GRADIENTS ARE A
BIT MARGINAL...H7 PROGS CONTINUE TO POINT TO THE POTENTIAL FOR A
HIGH WIND SET-UP EARLY TUESDAY. WILL KEEP THE HIGH WIND WARNING
GOING AS INHERITED.

WRAPAROUND MOISTURE WILL CONTINUE FOR A TIME NR THE PINE RIDGE
TUESDAY MORNING...BEFORE FINALLY LIFTING NORTHEAST BY MIDDAY. FLOW
WILL WESTERLY FOR TUESDAY...BUT THE CWFA WILL STILL BE INFLUENCED BY
THE LONGWAVE TROF OVER THE ROCKIES. A FEW SHOWERS AND ISOLATED
THUNDERSTORMS WILL STILL BE POSSIBLE...ESPECIALLY WEST OF THE
LARAMIE RANGE...ALTHOUGH COVERAGE WILL BE LESS.

THE NEXT FAST MOVING SHORTWAVE TROUGH WILL DIVE SOUTHEAST THRU THE
CWFA FOR WEDNESDAY. THIS WILL PROVIDE ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY OVR THE SOUTHEAST WYOMING MOUNTAINS AND
ADJACENT VALLEYS AND PLAINS. TEMPERATURES WILL WARM SLIGHTLY ON
TUESDAY...BACK INTO THE 60S MOST LOCATIONS WITH ANOTHER COOL DOWN
INTO THE 50S ANTICIPATED FOR WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 315 PM MDT MON SEP 29 2014

PRETTY QUIET EXTENDED PERIOD WITH PERSISTENT DRY NORTHWESTERLY FLOW
ALOFT IN PLACE.  SHORTWAVE WILL MOVE SOUTHEASTWARD FROM EASTERN
MONTANA INTO THE DAKOTAS DURING THE DAY ON THURS.  NO PRECIP IS
EXPECTED WITH THIS FEATURE AS IT WELL TO THE NORTHEAST. TEMPS WILL
BE SLIGHTLY BELOW NORMAL ON THURS WITH 700MB TEMPS AROUND 0C.  A
WARMING TREND WILL BEGIN ON FRI AND THEN CONTINUE INTO THE WEEKEND
WITH 700MB TEMPS RISING TO 5-10C.  ALTHOUGH THE STRONGEST FLOW ALOFT
IS OVER WESTERN SOUTH DAKOTA ON THURS THROUGH SUN...IT WILL STILL BE
BREEZY DURING THE AFTERNOONS ESPECIALLY ACROSS SOUTHEAST WY WITH
GOOD MIXING IN PLACE.  EXPECT WEST TO NORTHWEST WIND GUSTS TO 25-30
KTS ON MOST AFTNS.  PRECIP CHANCES AND CLOUD COVER WILL BE VERY
LIMITED THROUGH THE PERIOD WITH GENERAL RIDGING OVER THE
INTERMOUNTAIN WEST AND A LACK OF MOISTURE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1153 AM MDT MON SEP 29 2014

GOING TO GET A BREAK FROM THE RAIN AND LOWER CIGS THROUGH THE
EARLY AFTERNOON. WIDESPREAD MODERATE RAIN WITH EMBEDDED TSTMS IS
EXPECTED TO DEVELOP AT LAR AND CYS AROUND 21Z AND THEN SPREAD
NORTH AND EAST INTO THE NEBRASKA PANHANDLE DURING THE EARLY
EVENING. SINCE RAIN WILL LIKELY BE MODERATE TO HEAVY...WENT WITH
PREVAILING IFR CONDITIONS DURING THE EARLY EVENING OVER THE PLAINS
SITES. RAIN WILL LIKELY LINGER OVER THE NORTHERN PANHANDLE THROUGH
TUES MORNING. SOUTHEAST WINDS WILL BE GUSTY OVER THE PANHANDLE
THROUGH THE AFTN. A COLD FRONT WILL SWING ACROSS THE REGION AFTER
06Z WITH WINDS SWITCHING TO WEST AND SOUTHWEST. IT WILL BE WINDY
AFTER THE FRONTAL PASSAGE WITH GUSTS TO 30-35 KTS THROUGH THE
REMAINDER OF THE TAF PERIOD...ESPECIALLY OVER SOUTHEAST WY.


&&

.FIRE WEATHER...
ISSUED AT 315 PM MDT MON SEP 29 2014

A STRONG AREA OF LOW PRESSURE WILL LIFT NORTHEAST FROM THE FOUR
CORNERS INTO THE DISTRICTS THROUGH TONIGHT. THIS SYSTEM WILL BE
BRING WIDESPREAD WETTING RAINS TO A LARGE PART OF THE
DISTRICT...ESPECIALLY EAST OF THE LARAMIE RANGE. SOME AREAS IN THE
WESTERN NEBRASKA PANHANDLE PICKED UP 1-2 INCHES OF RAIN THIS
MORNING AND ARE IN LINE FOR ANOTHER 1-2 INCHES...PERHAPS LOCALLY
HIGHER TONIGHT AND EARLY TUESDAY. A FLOOD WATCH HAS BEEN ISSUED
FOR THE WESTERN NEBRASKA PANHANDLE THROUGH NOON TUESDAY. WIND
PRONE AREAS WEST OF THE LARAMIE RANGE WILL BECOME VERY WINDY LATE
TONIGHT AND EARLY TUESDAY...WHERE A HIGH WIND WARNING IS IN
EFFECT. THE COOL AND UNSETTLED WEATHER WILL CONTINUE TUESDAY AND
WEDNESDAY...THOUGH COVERAGE AND INTENSITY WILL BE LIGHTER.
TEMPERATURES WILL BEGIN WARMING UP FOR THE END OF THE WEEK AND
UPCOMING WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...FLOOD WATCH THROUGH TUESDAY MORNING FOR NEZ002-003-019>021-054-
     055-095-096.

&&

$$

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






000
FXUS65 KCYS 291805
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1205 PM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 1130 AM MDT MON SEP 29 2014

FIRST LINE OF SHOWERS AND THUNDERSTORMS ARE NOW EAST OF THE CWFA
FOR THE MOST PART WITH AMPLE SUNSHINE ACROSS MOST OF ALBANY...
LARAMIE AND PLATTE COUNTIES THIS MORNING. ATMOSPHERIC
DESTABILIZATION ALREADY UNDERWAY...WITH HIGH TEMPERATURES ALREADY
BEING REACHED IN THIS AREAS. IN A RECENT UPDATE HAVE BOOSTED HIGHS
3-4F ACROSS AREAS THAT HAVE ALREADY BROKEN OUT LATE THIS MORNING.
THIS WILL SET THE STAGE FOR CONVECTIVE RE-DEVELOPMENT EXPECTED BY
BETWEEN 1-2 PM PER LATEST HRRR OUTPUT. EVERYTHING STILL CONTINUES
TO POINT TO WIDESPREAD CONVECTION BY LATE THIS AFTERNOON AND THIS
EVENING ACROSS THE ERN PLAINS...SOME OF WHICH WILL HAVE SEVERE
POTENTIAL GENERALLY SOUTH AND EAST OF A CHEYENNE TO ALLIANCE LINE.
THE OTHER CONCERN IS WITH FLOODING POTENTIAL OVER THE WESTERN
NEBRASKA PANHANDLE. THESE AREAS HAVE ALREADY RECEIVED 1-2 INCHES
OF RAINFALL THIS MORNING...AND WITH ANOTHER 1-2...POTENTIALLY
HIGHER ON THE WAY LATER TODAY AND TONIGHT...THOUGH IT WAS PRUDENT
TO HOIST A FLOOD WATCH. WILL CONTINUE TO MONITOR DEVELOPMENTS
CLOSELY OVER THE NEXT FEW HOURS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM MDT MON SEP 29 2014

AN ACTIVE DAY OF WEATHER TODAY AS UPPER LEVEL LOW PRESSURE MOVES
INTO THE CENTRAL ROCKIES. SHOWERS AND THUNDERSTORMS CURRENTLY
NOTICEABLE ON RADAR IN ASSOCIATION WITH A VORTICITY LOBE WHICH IS
LIFTING NORTHWARD AHEAD OF THE MAIN UPPER LEVEL LOW. THIS ACTIVITY
SHOULD SUBSIDE SOMEWHAT THROUGH THIS MORNING BUT SHOULD CONTINUE
TO SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN
SHOT OF SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL THIS
MID AFTERNOON AS THE MAIN UPPER LEVEL LOW LIFTS INTO SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE. THIS IS A VERY DYNAMIC SYSTEM
AND WILL BRING WITH IT THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
SNOW TO THE MOUNTAINS.

CLOUD COVER THIS AFTERNOON MAY SERVE TO SLIGHTLY LIMIT THE
OVERALL THREAT FOR SEVERE STORMS...BUT REGARDLESS OF SURFACE
HEATING...UPPER LEVEL FORCING SHOULD MORE THAN COMPENSATE. STRONG
DIFFLUENT/DIVERGENT FLOW AND COOLING ALOFT WILL PRODUCE AMPLE
LIFT AND INSTABILITY RESPECTIVELY. THE MAIN SEVERE THREATS WILL BE
HAIL AND HEAVY RAIN...BUT STRONG WIND GUSTS WILL BE POSSIBLE...AS
WELL AS...TORNADOES. LCL HEIGHTS WILL BE VERY CLOSE TO THE GROUND
SUCH THAT ANY STRONG UPDRAFTS WILL NOT HAVE TO DO MUCH WORK TO
STRETCH AND TILT HORIZONTAL VORTICITY. MODELS SOLUTIONS ARE
SHOWING SOUTHEAST SURFACE WINDS OVER FAR SOUTHEAST WYOMING AND
MUCH OF THE NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING. WINDS
ALOFT QUICKLY VEER WITH HEIGHT WHICH IS ALSO FAVORABLE FOR TORNADO
GENESIS. THE MAIN TIME FRAME FOR SEVERE THUNDERSTORMS AND TORNADO
POTENTIAL WILL BE MID AFTERNOON THROUGH MID EVENING.

40 TO 50 KTS OF EFFECTIVE BULK SHEAR ALONG WITH ELEVATED CAPE
AROUND 1000 J/KG WILL BE ENOUGH TO PRODUCE ROBUST UPDRAFTS CAPABLE
OF PRODUCING LARGE HAIL. ALTHOUGH FREEZING LEVELS ARE RATHER HIGH
FOR THIS TIME OF YEAR...THEY WILL ONLY BE 7000 TO 9000 FEET AGL BY
00Z THIS EVENING AND FALLING. THIS MEANS HAILS STONES WILL HAVE
NOT HAVE MUCH TIME TO MELT BEFORE REACHING THE GROUND. WOULD NOT
BE COMPLETELY SURPRISED TO SEE HAIL TO THE SIZE OF GOLF BALLS WITH A
FEW STORMS LATE THIS AFTERNOON AND EARLY EVENING...PARTICULARLY
INTO THE NEBRASKA PANHANDLE. ALSO WORRIED ABOUT HEAVY RAIN. DUAL
POLE RADAR ALREADY SHOWING 1 TO 2 INCHES OF RAIN WITH LAST EVENING
AND OVERNIGHT CONVECTION FOR PORTIONS OF THE AREA. HEAVY RAINS OVER
THESE AREAS LATE TODAY AND TONIGHT MAY BE ENOUGH TO PRODUCE SOME
FLASH FLOODING. FORTUNATELY IT HAS BEEN DRY AS OF LATE SO GENERALLY
THE GROUND SHOULD BE ABLE TO HANDLE HEAVY RAIN...AS LONG AS THERE
IS NOT TOO MUCH TRAINING OF STORMS...WHICH IS POSSIBLE.

THE OTHER MAIN CONCERN IS FOR LATER TONIGHT AS WESTERLY WINDS
INCREASE AND STRONG SUBSIDENCE DEVELOPS BEHIND THE UPPER LOW.
SURFACE PRESSURE GRADIENTS WILL INCREASE AS SURFACE LOW PRESSURE
DEVELOPS IN THE NORTHERN PLAINS AND COLD AIR ADVECTS EASTWARD.
THESE FACTORS WILL LEAD TO THE DEVELOPMENT OF STRONG WEST
WINDS...MAINLY IN WIND PRONE AREAS OF SOUTHEAST WYOMING. HAVE
ISSUED A HIGH WIND WARNING FOR THE WIND PRONE AREAS SUCH AS THE
SOUTHERN LARAMIE RANGE AND FOOTHILLS...ARLINGTON...AND BORDEAUX.
HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON TUESDAY.
WILL ALSO HAVE TO KEEP AN EYE ON THE NORTHERN NEBRASKA PANHANDLE
FOR WIND ADVISORY POTENTIAL.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON SEP 29 2014

A GOOD CHANCE OF SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE
THROUGH EARLY WEDNESDAY NIGHT AS THE LAST UPPER LEVEL TROUGH WILL
PUSH EAST OF THE AREA BY EARLY THURSDAY MORNING. THE BEST CHANCE
FOR SHOWERS WILL BE ALONG AND SOUTH OF I80 AS THE TROUGH WILL BE
RATHER PROGRESSIVE. THE HIGHER MOUNTAINS ABOVE 8500 FEET WILL SEE
SNOWFALL INTO THURSDAY MORNING WITH A FEW INCHES OF ACCUMULATION
POSSIBLE. SNOW LEVEL SHOULD REMAIN ABOVE VALLEY FLOORS...ALTHOUGH
IT MAY GET CLOSE TO THE LARAMIE VALLEY FOR A TIME LATE WEDNESDAY
NIGHT. ALL MODELS IN AGREEMENT LATE NEXT WEEK SHOWING STRONG
NORTHWEST FLOW ALOFT RESULTING IN COOL TEMPERATURES FOR THURSDAY
AND FRIDAY...BUT DRIER CONDITIONS ARE EXPECTED AS THE POLAR JET
STREAM SHIFTS NORTHWARD INTO CANADA. TEMPERATURES ON THURSDAY WILL
REMAIN BELOW AVERAGE WITH HIGHS IN THE 50S TO MID 60S.

ALL MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED...SHOWING NORTHWEST
FLOW ALOFT CONTINUING INTO NEXT WEEK. HOWEVER...TEMPERATURES WILL
GRADUALLY INCREASE WITH HIGHS LIKELY AROUND 70 BY SATURDAY AND
SUNDAY AFTERNOON AS A RIDGE AXIS BUILDS ALONG THE WEST COAST AND
THEN DRIFTS EASTWARD. KEPT POP BELOW 10 PERCENT EACH DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1153 AM MDT MON SEP 29 2014

GOING TO GET A BREAK FROM THE RAIN AND LOWER CIGS THROUGH THE
EARLY AFTERNOON. WIDESPREAD MODERATE RAIN WITH EMBEDDED TSTMS IS
EXPECTED TO DEVELOP AT LAR AND CYS AROUND 21Z AND THEN SPREAD
NORTH AND EAST INTO THE NEBRASKA PANHANDLE DURING THE EARLY
EVENING. SINCE RAIN WILL LIKELY BE MODERATE TO HEAVY...WENT WITH
PREVAILING IFR CONDITIONS DURING THE EARLY EVENING OVER THE PLAINS
SITES. RAIN WILL LIKELY LINGER OVER THE NORTHERN PANHANDLE THROUGH
TUES MORNING. SOUTHEAST WINDS WILL BE GUSTY OVER THE PANHANDLE
THROUGH THE AFTN. A COLD FRONT WILL SWING ACROSS THE REGION AFTER
06Z WITH WINDS SWITCHING TO WEST AND SOUTHWEST. IT WILL BE WINDY
AFTER THE FRONTAL PASSAGE WITH GUSTS TO 30-35 KTS THROUGH THE
REMAINDER OF THE TAF PERIOD...ESPECIALLY OVER SOUTHEAST WY.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT MON SEP 29 2014

UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE FORECAST AREA
TODAY AND TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FOUND
OVER MOST OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TODAY. LESS
ACTIVITY IS EXPECTED INTO CARBON COUNTY WITH ISOLATED SHOWERS AND
THUNDERSTORMS OUTSIDE OF THE MOUNTAINS. SNOW ACCUMULATIONS LIKELY
INTO THE SNOWY AND SIERRA MADRE MOUNTAINS. STRONG WEST WINDS TO
DEVELOP TONIGHT OVER PORTIONS OF SOUTHEAST WYOMING. BREEZY TO WINDY
ACROSS THE AREA TUESDAY. COOL WEATHER WITH CHANCES FOR SHOWERS
TUESDAY AND WEDNESDAY. DRYING OUT AND WARMING UP LATE THIS WEEK AND
INTO THE WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...FLOOD WATCH FROM 3 PM MDT THIS AFTERNOON THROUGH TUESDAY MORNING
     FOR NEZ002-003-019>021-054-055-095-096.

&&

$$

UPDATE...HAHN
SHORT TERM...SML
LONG TERM...TJT
AVIATION...FINCH
FIRE WEATHER...SML





000
FXUS65 KCYS 291805
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1205 PM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 1130 AM MDT MON SEP 29 2014

FIRST LINE OF SHOWERS AND THUNDERSTORMS ARE NOW EAST OF THE CWFA
FOR THE MOST PART WITH AMPLE SUNSHINE ACROSS MOST OF ALBANY...
LARAMIE AND PLATTE COUNTIES THIS MORNING. ATMOSPHERIC
DESTABILIZATION ALREADY UNDERWAY...WITH HIGH TEMPERATURES ALREADY
BEING REACHED IN THIS AREAS. IN A RECENT UPDATE HAVE BOOSTED HIGHS
3-4F ACROSS AREAS THAT HAVE ALREADY BROKEN OUT LATE THIS MORNING.
THIS WILL SET THE STAGE FOR CONVECTIVE RE-DEVELOPMENT EXPECTED BY
BETWEEN 1-2 PM PER LATEST HRRR OUTPUT. EVERYTHING STILL CONTINUES
TO POINT TO WIDESPREAD CONVECTION BY LATE THIS AFTERNOON AND THIS
EVENING ACROSS THE ERN PLAINS...SOME OF WHICH WILL HAVE SEVERE
POTENTIAL GENERALLY SOUTH AND EAST OF A CHEYENNE TO ALLIANCE LINE.
THE OTHER CONCERN IS WITH FLOODING POTENTIAL OVER THE WESTERN
NEBRASKA PANHANDLE. THESE AREAS HAVE ALREADY RECEIVED 1-2 INCHES
OF RAINFALL THIS MORNING...AND WITH ANOTHER 1-2...POTENTIALLY
HIGHER ON THE WAY LATER TODAY AND TONIGHT...THOUGH IT WAS PRUDENT
TO HOIST A FLOOD WATCH. WILL CONTINUE TO MONITOR DEVELOPMENTS
CLOSELY OVER THE NEXT FEW HOURS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM MDT MON SEP 29 2014

AN ACTIVE DAY OF WEATHER TODAY AS UPPER LEVEL LOW PRESSURE MOVES
INTO THE CENTRAL ROCKIES. SHOWERS AND THUNDERSTORMS CURRENTLY
NOTICEABLE ON RADAR IN ASSOCIATION WITH A VORTICITY LOBE WHICH IS
LIFTING NORTHWARD AHEAD OF THE MAIN UPPER LEVEL LOW. THIS ACTIVITY
SHOULD SUBSIDE SOMEWHAT THROUGH THIS MORNING BUT SHOULD CONTINUE
TO SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN
SHOT OF SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL THIS
MID AFTERNOON AS THE MAIN UPPER LEVEL LOW LIFTS INTO SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE. THIS IS A VERY DYNAMIC SYSTEM
AND WILL BRING WITH IT THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
SNOW TO THE MOUNTAINS.

CLOUD COVER THIS AFTERNOON MAY SERVE TO SLIGHTLY LIMIT THE
OVERALL THREAT FOR SEVERE STORMS...BUT REGARDLESS OF SURFACE
HEATING...UPPER LEVEL FORCING SHOULD MORE THAN COMPENSATE. STRONG
DIFFLUENT/DIVERGENT FLOW AND COOLING ALOFT WILL PRODUCE AMPLE
LIFT AND INSTABILITY RESPECTIVELY. THE MAIN SEVERE THREATS WILL BE
HAIL AND HEAVY RAIN...BUT STRONG WIND GUSTS WILL BE POSSIBLE...AS
WELL AS...TORNADOES. LCL HEIGHTS WILL BE VERY CLOSE TO THE GROUND
SUCH THAT ANY STRONG UPDRAFTS WILL NOT HAVE TO DO MUCH WORK TO
STRETCH AND TILT HORIZONTAL VORTICITY. MODELS SOLUTIONS ARE
SHOWING SOUTHEAST SURFACE WINDS OVER FAR SOUTHEAST WYOMING AND
MUCH OF THE NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING. WINDS
ALOFT QUICKLY VEER WITH HEIGHT WHICH IS ALSO FAVORABLE FOR TORNADO
GENESIS. THE MAIN TIME FRAME FOR SEVERE THUNDERSTORMS AND TORNADO
POTENTIAL WILL BE MID AFTERNOON THROUGH MID EVENING.

40 TO 50 KTS OF EFFECTIVE BULK SHEAR ALONG WITH ELEVATED CAPE
AROUND 1000 J/KG WILL BE ENOUGH TO PRODUCE ROBUST UPDRAFTS CAPABLE
OF PRODUCING LARGE HAIL. ALTHOUGH FREEZING LEVELS ARE RATHER HIGH
FOR THIS TIME OF YEAR...THEY WILL ONLY BE 7000 TO 9000 FEET AGL BY
00Z THIS EVENING AND FALLING. THIS MEANS HAILS STONES WILL HAVE
NOT HAVE MUCH TIME TO MELT BEFORE REACHING THE GROUND. WOULD NOT
BE COMPLETELY SURPRISED TO SEE HAIL TO THE SIZE OF GOLF BALLS WITH A
FEW STORMS LATE THIS AFTERNOON AND EARLY EVENING...PARTICULARLY
INTO THE NEBRASKA PANHANDLE. ALSO WORRIED ABOUT HEAVY RAIN. DUAL
POLE RADAR ALREADY SHOWING 1 TO 2 INCHES OF RAIN WITH LAST EVENING
AND OVERNIGHT CONVECTION FOR PORTIONS OF THE AREA. HEAVY RAINS OVER
THESE AREAS LATE TODAY AND TONIGHT MAY BE ENOUGH TO PRODUCE SOME
FLASH FLOODING. FORTUNATELY IT HAS BEEN DRY AS OF LATE SO GENERALLY
THE GROUND SHOULD BE ABLE TO HANDLE HEAVY RAIN...AS LONG AS THERE
IS NOT TOO MUCH TRAINING OF STORMS...WHICH IS POSSIBLE.

THE OTHER MAIN CONCERN IS FOR LATER TONIGHT AS WESTERLY WINDS
INCREASE AND STRONG SUBSIDENCE DEVELOPS BEHIND THE UPPER LOW.
SURFACE PRESSURE GRADIENTS WILL INCREASE AS SURFACE LOW PRESSURE
DEVELOPS IN THE NORTHERN PLAINS AND COLD AIR ADVECTS EASTWARD.
THESE FACTORS WILL LEAD TO THE DEVELOPMENT OF STRONG WEST
WINDS...MAINLY IN WIND PRONE AREAS OF SOUTHEAST WYOMING. HAVE
ISSUED A HIGH WIND WARNING FOR THE WIND PRONE AREAS SUCH AS THE
SOUTHERN LARAMIE RANGE AND FOOTHILLS...ARLINGTON...AND BORDEAUX.
HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON TUESDAY.
WILL ALSO HAVE TO KEEP AN EYE ON THE NORTHERN NEBRASKA PANHANDLE
FOR WIND ADVISORY POTENTIAL.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON SEP 29 2014

A GOOD CHANCE OF SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE
THROUGH EARLY WEDNESDAY NIGHT AS THE LAST UPPER LEVEL TROUGH WILL
PUSH EAST OF THE AREA BY EARLY THURSDAY MORNING. THE BEST CHANCE
FOR SHOWERS WILL BE ALONG AND SOUTH OF I80 AS THE TROUGH WILL BE
RATHER PROGRESSIVE. THE HIGHER MOUNTAINS ABOVE 8500 FEET WILL SEE
SNOWFALL INTO THURSDAY MORNING WITH A FEW INCHES OF ACCUMULATION
POSSIBLE. SNOW LEVEL SHOULD REMAIN ABOVE VALLEY FLOORS...ALTHOUGH
IT MAY GET CLOSE TO THE LARAMIE VALLEY FOR A TIME LATE WEDNESDAY
NIGHT. ALL MODELS IN AGREEMENT LATE NEXT WEEK SHOWING STRONG
NORTHWEST FLOW ALOFT RESULTING IN COOL TEMPERATURES FOR THURSDAY
AND FRIDAY...BUT DRIER CONDITIONS ARE EXPECTED AS THE POLAR JET
STREAM SHIFTS NORTHWARD INTO CANADA. TEMPERATURES ON THURSDAY WILL
REMAIN BELOW AVERAGE WITH HIGHS IN THE 50S TO MID 60S.

ALL MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED...SHOWING NORTHWEST
FLOW ALOFT CONTINUING INTO NEXT WEEK. HOWEVER...TEMPERATURES WILL
GRADUALLY INCREASE WITH HIGHS LIKELY AROUND 70 BY SATURDAY AND
SUNDAY AFTERNOON AS A RIDGE AXIS BUILDS ALONG THE WEST COAST AND
THEN DRIFTS EASTWARD. KEPT POP BELOW 10 PERCENT EACH DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1153 AM MDT MON SEP 29 2014

GOING TO GET A BREAK FROM THE RAIN AND LOWER CIGS THROUGH THE
EARLY AFTERNOON. WIDESPREAD MODERATE RAIN WITH EMBEDDED TSTMS IS
EXPECTED TO DEVELOP AT LAR AND CYS AROUND 21Z AND THEN SPREAD
NORTH AND EAST INTO THE NEBRASKA PANHANDLE DURING THE EARLY
EVENING. SINCE RAIN WILL LIKELY BE MODERATE TO HEAVY...WENT WITH
PREVAILING IFR CONDITIONS DURING THE EARLY EVENING OVER THE PLAINS
SITES. RAIN WILL LIKELY LINGER OVER THE NORTHERN PANHANDLE THROUGH
TUES MORNING. SOUTHEAST WINDS WILL BE GUSTY OVER THE PANHANDLE
THROUGH THE AFTN. A COLD FRONT WILL SWING ACROSS THE REGION AFTER
06Z WITH WINDS SWITCHING TO WEST AND SOUTHWEST. IT WILL BE WINDY
AFTER THE FRONTAL PASSAGE WITH GUSTS TO 30-35 KTS THROUGH THE
REMAINDER OF THE TAF PERIOD...ESPECIALLY OVER SOUTHEAST WY.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT MON SEP 29 2014

UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE FORECAST AREA
TODAY AND TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FOUND
OVER MOST OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TODAY. LESS
ACTIVITY IS EXPECTED INTO CARBON COUNTY WITH ISOLATED SHOWERS AND
THUNDERSTORMS OUTSIDE OF THE MOUNTAINS. SNOW ACCUMULATIONS LIKELY
INTO THE SNOWY AND SIERRA MADRE MOUNTAINS. STRONG WEST WINDS TO
DEVELOP TONIGHT OVER PORTIONS OF SOUTHEAST WYOMING. BREEZY TO WINDY
ACROSS THE AREA TUESDAY. COOL WEATHER WITH CHANCES FOR SHOWERS
TUESDAY AND WEDNESDAY. DRYING OUT AND WARMING UP LATE THIS WEEK AND
INTO THE WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...FLOOD WATCH FROM 3 PM MDT THIS AFTERNOON THROUGH TUESDAY MORNING
     FOR NEZ002-003-019>021-054-055-095-096.

&&

$$

UPDATE...HAHN
SHORT TERM...SML
LONG TERM...TJT
AVIATION...FINCH
FIRE WEATHER...SML






000
FXUS65 KCYS 291731
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1131 AM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 1130 AM MDT MON SEP 29 2014

FIRST LINE OF SHOWERS AND THUNDERSTORMS ARE NOW EAST OF THE CWFA
FOR THE MOST PART WITH AMPLE SUNSHINE ACROSS MOST OF ALBANY...
LARAMIE AND PLATTE COUNTIES THIS MORNING. ATMOSPHERIC
DESTABILZIATION ALREADY UNDERWAY...WITH HIGH TEMPERATURES ALREADY
BEING REACHED IN THIS AREAS. IN A RECENT UPDATE HAVE BOOSTED HIGHS
3-4F ACROSS AREAS THAT HAVE ALREADY BROKEN OUT LATE THIS MORNING.
THIS WILL SET THE STAGE FOR CONVECTIVE RE-DEVEOPMENT EXPECTED BY
BETWEEN 1-2 PM PER LATEST HRRR OUTPUT. EVERYTHING STILL CONTINUES
TO POINT TO WIDESPREAD CONVECTION BY LATE THIS AFTERNOON AND THIS
EVENING ACROSS THE ERN PLAINS...SOME OF WHICH WILL HAVE SEVERE
POTENTIAL GENERALLY SOUTH AND EAST OF A CHEYENNE TO ALLIANCE LINE.
THE OTHER CONCERN IS WITH FLOODING POTENTIAL OVER THE WESTERN
NEBRASKA PANHANDLE. THESE AREAS HAVE ALREADY RECEIVED 1-2 INCHES
OF RAINFALL THIS MORNING...AND WITH ANOTHER 1-2...POTENTIALLY
HIGHER ON THE WAY LATER TODAY AND TONIGHT...THOUGH IT WAS PRUDENT
TO HOIST A FLOOD WATCH. WILL CONTINUE TO MONITOR DEVELOPMENTS
CLOSELY OVER THE NEXT FEW HOURS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM MDT MON SEP 29 2014

AN ACTIVE DAY OF WEATHER TODAY AS UPPER LEVEL LOW PRESSURE MOVES
INTO THE CENTRAL ROCKIES. SHOWERS AND THUNDERSTORMS CURRENTLY
NOTICEABLE ON RADAR IN ASSOCIATION WITH A VORTICITY LOBE WHICH IS
LIFTING NORTHWARD AHEAD OF THE MAIN UPPER LEVEL LOW. THIS ACTIVITY
SHOULD SUBSIDE SOMEWHAT THROUGH THIS MORNING BUT SHOULD CONTINUE
TO SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN
SHOT OF SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL THIS
MID AFTERNOON AS THE MAIN UPPER LEVEL LOW LIFTS INTO SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE. THIS IS A VERY DYNAMIC SYSTEM
AND WILL BRING WITH IT THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
SNOW TO THE MOUNTAINS.

CLOUD COVER THIS AFTERNOON MAY SERVE TO SLIGHTLY LIMIT THE
OVERALL THREAT FOR SEVERE STORMS...BUT REGARDLESS OF SURFACE
HEATING...UPPER LEVEL FORCING SHOULD MORE THAN COMPENSATE. STRONG
DIFFLUENT/DIVERGENT FLOW AND COOLING ALOFT WILL PRODUCE AMPLE
LIFT AND INSTABILITY RESPECTIVELY. THE MAIN SEVERE THREATS WILL BE
HAIL AND HEAVY RAIN...BUT STRONG WIND GUSTS WILL BE POSSIBLE...AS
WELL AS...TORNADOES. LCL HEIGHTS WILL BE VERY CLOSE TO THE GROUND
SUCH THAT ANY STRONG UPDRAFTS WILL NOT HAVE TO DO MUCH WORK TO
STRETCH AND TILT HORIZONTAL VORTICITY. MODELS SOLUTIONS ARE
SHOWING SOUTHEAST SURFACE WINDS OVER FAR SOUTHEAST WYOMING AND
MUCH OF THE NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING. WINDS
ALOFT QUICKLY VEER WITH HEIGHT WHICH IS ALSO FAVORABLE FOR TORNADO
GENESIS. THE MAIN TIME FRAME FOR SEVERE THUNDERSTORMS AND TORNADO
POTENTIAL WILL BE MID AFTERNOON THROUGH MID EVENING.

40 TO 50 KTS OF EFFECTIVE BULK SHEAR ALONG WITH ELEVATED CAPE
AROUND 1000 J/KG WILL BE ENOUGH TO PRODUCE ROBUST UPDRAFTS CAPABLE
OF PRODUCING LARGE HAIL. ALTHOUGH FREEZING LEVELS ARE RATHER HIGH
FOR THIS TIME OF YEAR...THEY WILL ONLY BE 7000 TO 9000 FEET AGL BY
00Z THIS EVENING AND FALLING. THIS MEANS HAILS STONES WILL HAVE
NOT HAVE MUCH TIME TO MELT BEFORE REACHING THE GROUND. WOULD NOT
BE COMPLETELY SURPRISED TO SEE HAIL TO THE SIZE OF GOLF BALLS WITH A
FEW STORMS LATE THIS AFTERNOON AND EARLY EVENING...PARTICULARLY
INTO THE NEBRASKA PANHANDLE. ALSO WORRIED ABOUT HEAVY RAIN. DUAL
POLE RADAR ALREADY SHOWING 1 TO 2 INCHES OF RAIN WITH LAST EVENING
AND OVERNIGHT CONVECTION FOR PORTIONS OF THE AREA. HEAVY RAINS OVER
THESE AREAS LATE TODAY AND TONIGHT MAY BE ENOUGH TO PRODUCE SOME
FLASH FLOODING. FORTUNATELY IT HAS BEEN DRY AS OF LATE SO GENERALLY
THE GROUND SHOULD BE ABLE TO HANDLE HEAVY RAIN...AS LONG AS THERE
IS NOT TOO MUCH TRAINING OF STORMS...WHICH IS POSSIBLE.

THE OTHER MAIN CONCERN IS FOR LATER TONIGHT AS WESTERLY WINDS
INCREASE AND STRONG SUBSIDENCE DEVELOPS BEHIND THE UPPER LOW.
SURFACE PRESSURE GRADIENTS WILL INCREASE AS SURFACE LOW PRESSURE
DEVELOPS IN THE NORTHERN PLAINS AND COLD AIR ADVECTS EASTWARD.
THESE FACTORS WILL LEAD TO THE DEVELOPMENT OF STRONG WEST
WINDS...MAINLY IN WIND PRONE AREAS OF SOUTHEAST WYOMING. HAVE
ISSUED A HIGH WIND WARNING FOR THE WIND PRONE AREAS SUCH AS THE
SOUTHERN LARAMIE RANGE AND FOOTHILLS...ARLINGTON...AND BORDEAUX.
HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON TUESDAY.
WILL ALSO HAVE TO KEEP AN EYE ON THE NORTHERN NEBRASKA PANHANDLE
FOR WIND ADVISORY POTENTIAL.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON SEP 29 2014

A GOOD CHANCE OF SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE
THROUGH EARLY WEDNESDAY NIGHT AS THE LAST UPPER LEVEL TROUGH WILL
PUSH EAST OF THE AREA BY EARLY THURSDAY MORNING. THE BEST CHANCE
FOR SHOWERS WILL BE ALONG AND SOUTH OF I80 AS THE TROUGH WILL BE
RATHER PROGRESSIVE. THE HIGHER MOUNTAINS ABOVE 8500 FEET WILL SEE
SNOWFALL INTO THURSDAY MORNING WITH A FEW INCHES OF ACCUMULATION
POSSIBLE. SNOW LEVEL SHOULD REMAIN ABOVE VALLEY FLOORS...ALTHOUGH
IT MAY GET CLOSE TO THE LARAMIE VALLEY FOR A TIME LATE WEDNESDAY
NIGHT. ALL MODELS IN AGREEMENT LATE NEXT WEEK SHOWING STRONG
NORTHWEST FLOW ALOFT RESULTING IN COOL TEMPERATURES FOR THURSDAY
AND FRIDAY...BUT DRIER CONDITIONS ARE EXPECTED AS THE POLAR JET
STREAM SHIFTS NORTHWARD INTO CANADA. TEMPERATURES ON THURSDAY WILL
REMAIN BELOW AVERAGE WITH HIGHS IN THE 50S TO MID 60S.

ALL MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED...SHOWING NORTHWEST
FLOW ALOFT CONTINUING INTO NEXT WEEK. HOWEVER...TEMPERATURES WILL
GRADUALLY INCREASE WITH HIGHS LIKELY AROUND 70 BY SATURDAY AND
SUNDAY AFTERNOON AS A RIDGE AXIS BUILDS ALONG THE WEST COAST AND
THEN DRIFTS EASTWARD. KEPT POP BELOW 10 PERCENT EACH DAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH MONDAY NIGHT)
ISSUED AT 420 AM MDT MON SEP 29 2014

SCATTERED SHOWERS AND TSTORMS WILL CONTINUE THIS MORNING ACROSS
THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS A STRONG STORM SYSTEM
SLOWLY MOVES EASTWARD INTO THE ROCKY MOUNTAINS. BETWEEN THE
INDIVIDUAL TSTORM CELLS...AREAS OF FOG AND LOW STRATUS WILL
PERSIST THROUGH SUNRISE WITH IFR CONDITIONS EXPECTED. CONDITIONS
WILL SLOWLY IMPROVE LATER THIS MORNING...WITH LIGHT RAIN/DRIZZLE
CONTINUING OVER MOST EASTERN SITES THROUGH LATE MORNING. THIS
BRIEF LULL IN THE ACTION WILL NOT LAST LONG HOWEVER...AS
CONVECTION WILL RAPIDLY REDEVELOP OVER THE MOUNTAINS IN THE EARLY
AFTERNOON AND WILL MOVE NORTHEAST THROUGH THE AFTERNOON/EVENING
HOURS ACROSS THE PLAINS. STORMS ARE EXPECTED TO ONCE AGAIN PRODUCE
MVFR/IFR CONDITIONS IN MODERATE TO HEAVY RAIN...WITH SOME STORMS
POSSIBLY BECOMING STRONG OR SEVERE OVER EXTREME SOUTHEAST WYOMING
AND THE SOUTHERN PANHANDLE.

WINDS WILL RAPIDLY SHIFT INTO THE WEST LATER TONIGHT BRINGING
DRIER AIR TO THE REGION BUT ALSO THE THREAT OF STRONG GUSTY WINDS
OVER 45 KNOTS...MAINLY AFTER MIDNIGHT.


&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT MON SEP 29 2014

UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE FORECAST AREA
TODAY AND TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FOUND
OVER MOST OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TODAY. LESS
ACTIVITY IS EXPECTED INTO CARBON COUNTY WITH ISOLATED SHOWERS AND
THUNDERSTORMS OUTSIDE OF THE MOUNTAINS. SNOW ACCUMULATIONS LIKELY
INTO THE SNOWY AND SIERRA MADRE MOUNTAINS. STRONG WEST WINDS TO
DEVELOP TONIGHT OVER PORTIONS OF SOUTHEAST WYOMING. BREEZY TO WINDY
ACROSS THE AREA TUESDAY. COOL WEATHER WITH CHANCES FOR SHOWERS
TUESDAY AND WEDNESDAY. DRYING OUT AND WARMING UP LATE THIS WEEK AND
INTO THE WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...NONE.
&&

$$

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







000
FXUS65 KCYS 291731
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1131 AM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 1130 AM MDT MON SEP 29 2014

FIRST LINE OF SHOWERS AND THUNDERSTORMS ARE NOW EAST OF THE CWFA
FOR THE MOST PART WITH AMPLE SUNSHINE ACROSS MOST OF ALBANY...
LARAMIE AND PLATTE COUNTIES THIS MORNING. ATMOSPHERIC
DESTABILZIATION ALREADY UNDERWAY...WITH HIGH TEMPERATURES ALREADY
BEING REACHED IN THIS AREAS. IN A RECENT UPDATE HAVE BOOSTED HIGHS
3-4F ACROSS AREAS THAT HAVE ALREADY BROKEN OUT LATE THIS MORNING.
THIS WILL SET THE STAGE FOR CONVECTIVE RE-DEVEOPMENT EXPECTED BY
BETWEEN 1-2 PM PER LATEST HRRR OUTPUT. EVERYTHING STILL CONTINUES
TO POINT TO WIDESPREAD CONVECTION BY LATE THIS AFTERNOON AND THIS
EVENING ACROSS THE ERN PLAINS...SOME OF WHICH WILL HAVE SEVERE
POTENTIAL GENERALLY SOUTH AND EAST OF A CHEYENNE TO ALLIANCE LINE.
THE OTHER CONCERN IS WITH FLOODING POTENTIAL OVER THE WESTERN
NEBRASKA PANHANDLE. THESE AREAS HAVE ALREADY RECEIVED 1-2 INCHES
OF RAINFALL THIS MORNING...AND WITH ANOTHER 1-2...POTENTIALLY
HIGHER ON THE WAY LATER TODAY AND TONIGHT...THOUGH IT WAS PRUDENT
TO HOIST A FLOOD WATCH. WILL CONTINUE TO MONITOR DEVELOPMENTS
CLOSELY OVER THE NEXT FEW HOURS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM MDT MON SEP 29 2014

AN ACTIVE DAY OF WEATHER TODAY AS UPPER LEVEL LOW PRESSURE MOVES
INTO THE CENTRAL ROCKIES. SHOWERS AND THUNDERSTORMS CURRENTLY
NOTICEABLE ON RADAR IN ASSOCIATION WITH A VORTICITY LOBE WHICH IS
LIFTING NORTHWARD AHEAD OF THE MAIN UPPER LEVEL LOW. THIS ACTIVITY
SHOULD SUBSIDE SOMEWHAT THROUGH THIS MORNING BUT SHOULD CONTINUE
TO SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN
SHOT OF SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL THIS
MID AFTERNOON AS THE MAIN UPPER LEVEL LOW LIFTS INTO SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE. THIS IS A VERY DYNAMIC SYSTEM
AND WILL BRING WITH IT THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
SNOW TO THE MOUNTAINS.

CLOUD COVER THIS AFTERNOON MAY SERVE TO SLIGHTLY LIMIT THE
OVERALL THREAT FOR SEVERE STORMS...BUT REGARDLESS OF SURFACE
HEATING...UPPER LEVEL FORCING SHOULD MORE THAN COMPENSATE. STRONG
DIFFLUENT/DIVERGENT FLOW AND COOLING ALOFT WILL PRODUCE AMPLE
LIFT AND INSTABILITY RESPECTIVELY. THE MAIN SEVERE THREATS WILL BE
HAIL AND HEAVY RAIN...BUT STRONG WIND GUSTS WILL BE POSSIBLE...AS
WELL AS...TORNADOES. LCL HEIGHTS WILL BE VERY CLOSE TO THE GROUND
SUCH THAT ANY STRONG UPDRAFTS WILL NOT HAVE TO DO MUCH WORK TO
STRETCH AND TILT HORIZONTAL VORTICITY. MODELS SOLUTIONS ARE
SHOWING SOUTHEAST SURFACE WINDS OVER FAR SOUTHEAST WYOMING AND
MUCH OF THE NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING. WINDS
ALOFT QUICKLY VEER WITH HEIGHT WHICH IS ALSO FAVORABLE FOR TORNADO
GENESIS. THE MAIN TIME FRAME FOR SEVERE THUNDERSTORMS AND TORNADO
POTENTIAL WILL BE MID AFTERNOON THROUGH MID EVENING.

40 TO 50 KTS OF EFFECTIVE BULK SHEAR ALONG WITH ELEVATED CAPE
AROUND 1000 J/KG WILL BE ENOUGH TO PRODUCE ROBUST UPDRAFTS CAPABLE
OF PRODUCING LARGE HAIL. ALTHOUGH FREEZING LEVELS ARE RATHER HIGH
FOR THIS TIME OF YEAR...THEY WILL ONLY BE 7000 TO 9000 FEET AGL BY
00Z THIS EVENING AND FALLING. THIS MEANS HAILS STONES WILL HAVE
NOT HAVE MUCH TIME TO MELT BEFORE REACHING THE GROUND. WOULD NOT
BE COMPLETELY SURPRISED TO SEE HAIL TO THE SIZE OF GOLF BALLS WITH A
FEW STORMS LATE THIS AFTERNOON AND EARLY EVENING...PARTICULARLY
INTO THE NEBRASKA PANHANDLE. ALSO WORRIED ABOUT HEAVY RAIN. DUAL
POLE RADAR ALREADY SHOWING 1 TO 2 INCHES OF RAIN WITH LAST EVENING
AND OVERNIGHT CONVECTION FOR PORTIONS OF THE AREA. HEAVY RAINS OVER
THESE AREAS LATE TODAY AND TONIGHT MAY BE ENOUGH TO PRODUCE SOME
FLASH FLOODING. FORTUNATELY IT HAS BEEN DRY AS OF LATE SO GENERALLY
THE GROUND SHOULD BE ABLE TO HANDLE HEAVY RAIN...AS LONG AS THERE
IS NOT TOO MUCH TRAINING OF STORMS...WHICH IS POSSIBLE.

THE OTHER MAIN CONCERN IS FOR LATER TONIGHT AS WESTERLY WINDS
INCREASE AND STRONG SUBSIDENCE DEVELOPS BEHIND THE UPPER LOW.
SURFACE PRESSURE GRADIENTS WILL INCREASE AS SURFACE LOW PRESSURE
DEVELOPS IN THE NORTHERN PLAINS AND COLD AIR ADVECTS EASTWARD.
THESE FACTORS WILL LEAD TO THE DEVELOPMENT OF STRONG WEST
WINDS...MAINLY IN WIND PRONE AREAS OF SOUTHEAST WYOMING. HAVE
ISSUED A HIGH WIND WARNING FOR THE WIND PRONE AREAS SUCH AS THE
SOUTHERN LARAMIE RANGE AND FOOTHILLS...ARLINGTON...AND BORDEAUX.
HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON TUESDAY.
WILL ALSO HAVE TO KEEP AN EYE ON THE NORTHERN NEBRASKA PANHANDLE
FOR WIND ADVISORY POTENTIAL.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON SEP 29 2014

A GOOD CHANCE OF SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE
THROUGH EARLY WEDNESDAY NIGHT AS THE LAST UPPER LEVEL TROUGH WILL
PUSH EAST OF THE AREA BY EARLY THURSDAY MORNING. THE BEST CHANCE
FOR SHOWERS WILL BE ALONG AND SOUTH OF I80 AS THE TROUGH WILL BE
RATHER PROGRESSIVE. THE HIGHER MOUNTAINS ABOVE 8500 FEET WILL SEE
SNOWFALL INTO THURSDAY MORNING WITH A FEW INCHES OF ACCUMULATION
POSSIBLE. SNOW LEVEL SHOULD REMAIN ABOVE VALLEY FLOORS...ALTHOUGH
IT MAY GET CLOSE TO THE LARAMIE VALLEY FOR A TIME LATE WEDNESDAY
NIGHT. ALL MODELS IN AGREEMENT LATE NEXT WEEK SHOWING STRONG
NORTHWEST FLOW ALOFT RESULTING IN COOL TEMPERATURES FOR THURSDAY
AND FRIDAY...BUT DRIER CONDITIONS ARE EXPECTED AS THE POLAR JET
STREAM SHIFTS NORTHWARD INTO CANADA. TEMPERATURES ON THURSDAY WILL
REMAIN BELOW AVERAGE WITH HIGHS IN THE 50S TO MID 60S.

ALL MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED...SHOWING NORTHWEST
FLOW ALOFT CONTINUING INTO NEXT WEEK. HOWEVER...TEMPERATURES WILL
GRADUALLY INCREASE WITH HIGHS LIKELY AROUND 70 BY SATURDAY AND
SUNDAY AFTERNOON AS A RIDGE AXIS BUILDS ALONG THE WEST COAST AND
THEN DRIFTS EASTWARD. KEPT POP BELOW 10 PERCENT EACH DAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH MONDAY NIGHT)
ISSUED AT 420 AM MDT MON SEP 29 2014

SCATTERED SHOWERS AND TSTORMS WILL CONTINUE THIS MORNING ACROSS
THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS A STRONG STORM SYSTEM
SLOWLY MOVES EASTWARD INTO THE ROCKY MOUNTAINS. BETWEEN THE
INDIVIDUAL TSTORM CELLS...AREAS OF FOG AND LOW STRATUS WILL
PERSIST THROUGH SUNRISE WITH IFR CONDITIONS EXPECTED. CONDITIONS
WILL SLOWLY IMPROVE LATER THIS MORNING...WITH LIGHT RAIN/DRIZZLE
CONTINUING OVER MOST EASTERN SITES THROUGH LATE MORNING. THIS
BRIEF LULL IN THE ACTION WILL NOT LAST LONG HOWEVER...AS
CONVECTION WILL RAPIDLY REDEVELOP OVER THE MOUNTAINS IN THE EARLY
AFTERNOON AND WILL MOVE NORTHEAST THROUGH THE AFTERNOON/EVENING
HOURS ACROSS THE PLAINS. STORMS ARE EXPECTED TO ONCE AGAIN PRODUCE
MVFR/IFR CONDITIONS IN MODERATE TO HEAVY RAIN...WITH SOME STORMS
POSSIBLY BECOMING STRONG OR SEVERE OVER EXTREME SOUTHEAST WYOMING
AND THE SOUTHERN PANHANDLE.

WINDS WILL RAPIDLY SHIFT INTO THE WEST LATER TONIGHT BRINGING
DRIER AIR TO THE REGION BUT ALSO THE THREAT OF STRONG GUSTY WINDS
OVER 45 KNOTS...MAINLY AFTER MIDNIGHT.


&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT MON SEP 29 2014

UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE FORECAST AREA
TODAY AND TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FOUND
OVER MOST OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TODAY. LESS
ACTIVITY IS EXPECTED INTO CARBON COUNTY WITH ISOLATED SHOWERS AND
THUNDERSTORMS OUTSIDE OF THE MOUNTAINS. SNOW ACCUMULATIONS LIKELY
INTO THE SNOWY AND SIERRA MADRE MOUNTAINS. STRONG WEST WINDS TO
DEVELOP TONIGHT OVER PORTIONS OF SOUTHEAST WYOMING. BREEZY TO WINDY
ACROSS THE AREA TUESDAY. COOL WEATHER WITH CHANCES FOR SHOWERS
TUESDAY AND WEDNESDAY. DRYING OUT AND WARMING UP LATE THIS WEEK AND
INTO THE WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...NONE.
&&

$$

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








000
FXUS65 KCYS 291239 CCA
AFDCYS

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE CHEYENNE WY
639 AM MDT MON SEP 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM MDT MON SEP 29 2014

AN ACTIVE DAY OF WEATHER TODAY AS UPPER LEVEL LOW PRESSURE MOVES
INTO THE CENTRAL ROCKIES. SHOWERS AND THUNDERSTORMS CURRENTLY
NOTICEABLE ON RADAR IN ASSOCIATION WITH A VORTICITY LOBE WHICH IS
LIFTING NORTHWARD AHEAD OF THE MAIN UPPER LEVEL LOW. THIS ACTIVITY
SHOULD SUBSIDE SOMEWHAT THROUGH THIS MORNING BUT SHOULD CONTINUE
TO SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN
SHOT OF SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL THIS
MID AFTERNOON AS THE MAIN UPPER LEVEL LOW LIFTS INTO SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE. THIS IS A VERY DYNAMIC SYSTEM
AND WILL BRING WITH IT THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
SNOW TO THE MOUNTAINS.

CLOUD COVER THIS AFTERNOON MAY SERVE TO SLIGHTLY LIMIT THE
OVERALL THREAT FOR SEVERE STORMS...BUT REGARDLESS OF SURFACE
HEATING...UPPER LEVEL FORCING SHOULD MORE THAN COMPENSATE. STRONG
DIFFLUENT/DIVERGENT FLOW AND COOLING ALOFT WILL PRODUCE AMPLE
LIFT AND INSTABILITY RESPECTIVELY. THE MAIN SEVERE THREATS WILL BE
HAIL AND HEAVY RAIN...BUT STRONG WIND GUSTS WILL BE POSSIBLE...AS
WELL AS...TORNADOES. LCL HEIGHTS WILL BE VERY CLOSE TO THE GROUND
SUCH THAT ANY STRONG UPDRAFTS WILL NOT HAVE TO DO MUCH WORK TO
STRETCH AND TILT HORIZONTAL VORTICITY. MODELS SOLUTIONS ARE
SHOWING SOUTHEAST SURFACE WINDS OVER FAR SOUTHEAST WYOMING AND
MUCH OF THE NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING. WINDS
ALOFT QUICKLY VEER WITH HEIGHT WHICH IS ALSO FAVORABLE FOR TORNADO
GENESIS. THE MAIN TIME FRAME FOR SEVERE THUNDERSTORMS AND TORNADO
POTENTIAL WILL BE MID AFTERNOON THROUGH MID EVENING.

40 TO 50 KTS OF EFFECTIVE BULK SHEAR ALONG WITH ELEVATED CAPE
AROUND 1000 J/KG WILL BE ENOUGH TO PRODUCE ROBUST UPDRAFTS CAPABLE
OF PRODUCING LARGE HAIL. ALTHOUGH FREEZING LEVELS ARE RATHER HIGH
FOR THIS TIME OF YEAR...THEY WILL ONLY BE 7000 TO 9000 FEET AGL BY
00Z THIS EVENING AND FALLING. THIS MEANS HAILS STONES WILL HAVE
NOT HAVE MUCH TIME TO MELT BEFORE REACHING THE GROUND. WOULD NOT
BE COMPLETELY SURPRISED TO SEE HAIL TO THE SIZE OF GOLF BALLS WITH A
FEW STORMS LATE THIS AFTERNOON AND EARLY EVENING...PARTICULARLY
INTO THE NEBRASKA PANHANDLE. ALSO WORRIED ABOUT HEAVY RAIN. DUAL
POLE RADAR ALREADY SHOWING 1 TO 2 INCHES OF RAIN WITH LAST EVENING
AND OVERNIGHT CONVECTION FOR PORTIONS OF THE AREA. HEAVY RAINS OVER
THESE AREAS LATE TODAY AND TONIGHT MAY BE ENOUGH TO PRODUCE SOME
FLASH FLOODING. FORTUNATELY IT HAS BEEN DRY AS OF LATE SO GENERALLY
THE GROUND SHOULD BE ABLE TO HANDLE HEAVY RAIN...AS LONG AS THERE
IS NOT TOO MUCH TRAINING OF STORMS...WHICH IS POSSIBLE.

THE OTHER MAIN CONCERN IS FOR LATER TONIGHT AS WESTERLY WINDS
INCREASE AND STRONG SUBSIDENCE DEVELOPS BEHIND THE UPPER LOW.
SURFACE PRESSURE GRADIENTS WILL INCREASE AS SURFACE LOW PRESSURE
DEVELOPS IN THE NORTHERN PLAINS AND COLD AIR ADVECTS EASTWARD.
THESE FACTORS WILL LEAD TO THE DEVELOPMENT OF STRONG WEST
WINDS...MAINLY IN WIND PRONE AREAS OF SOUTHEAST WYOMING. HAVE
ISSUED A HIGH WIND WARNING FOR THE WIND PRONE AREAS SUCH AS THE
SOUTHERN LARAMIE RANGE AND FOOTHILLS...ARLINGTON...AND BORDEAUX.
HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON TUESDAY.
WILL ALSO HAVE TO KEEP AN EYE ON THE NORTHERN NEBRASKA PANHANDLE
FOR WIND ADVISORY POTENTIAL.


.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON SEP 29 2014

A GOOD CHANCE OF SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE
THROUGH EARLY WEDNESDAY NIGHT AS THE LAST UPPER LEVEL TROUGH WILL
PUSH EAST OF THE AREA BY EARLY THURSDAY MORNING. THE BEST CHANCE
FOR SHOWERS WILL BE ALONG AND SOUTH OF I80 AS THE TROUGH WILL BE
RATHER PROGRESSIVE. THE HIGHER MOUNTAINS ABOVE 8500 FEET WILL SEE
SNOWFALL INTO THURSDAY MORNING WITH A FEW INCHES OF ACCUMULATION
POSSIBLE. SNOW LEVEL SHOULD REMAIN ABOVE VALLEY FLOORS...ALTHOUGH
IT MAY GET CLOSE TO THE LARAMIE VALLEY FOR A TIME LATE WEDNESDAY
NIGHT. ALL MODELS IN AGREEMENT LATE NEXT WEEK SHOWING STRONG
NORTHWEST FLOW ALOFT RESULTING IN COOL TEMPERATURES FOR THURSDAY
AND FRIDAY...BUT DRIER CONDITIONS ARE EXPECTED AS THE POLAR JET
STREAM SHIFTS NORTHWARD INTO CANADA. TEMPERATURES ON THURSDAY WILL
REMAIN BELOW AVERAGE WITH HIGHS IN THE 50S TO MID 60S.

ALL MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED...SHOWING NORTHWEST
FLOW ALOFT CONTINUING INTO NEXT WEEK. HOWEVER...TEMPERATURES WILL
GRADUALLY INCREASE WITH HIGHS LIKELY AROUND 70 BY SATURDAY AND
SUNDAY AFTERNOON AS A RIDGE AXIS BUILDS ALONG THE WEST COAST AND
THEN DRIFTS EASTWARD. KEPT POP BELOW 10 PERCENT EACH DAY.


&&

.AVIATION...(FOR THE 12Z TAFS THROUGH MONDAY NIGHT)
ISSUED AT 420 AM MDT MON SEP 29 2014

SCATTERED SHOWERS AND TSTORMS WILL CONTINUE THIS MORNING ACROSS
THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS A STRONG STORM SYSTEM
SLOWLY MOVES EASTWARD INTO THE ROCKY MOUNTAINS. BETWEEN THE
INDIVIDUAL TSTORM CELLS...AREAS OF FOG AND LOW STRATUS WILL
PERSIST THROUGH SUNRISE WITH IFR CONDITIONS EXPECTED. CONDITIONS
WILL SLOWLY IMPROVE LATER THIS MORNING...WITH LIGHT RAIN/DRIZZLE
CONTINUING OVER MOST EASTERN SITES THROUGH LATE MORNING. THIS
BRIEF LULL IN THE ACTION WILL NOT LAST LONG HOWEVER...AS
CONVECTION WILL RAPIDLY REDEVELOP OVER THE MOUNTAINS IN THE EARLY
AFTERNOON AND WILL MOVE NORTHEAST THROUGH THE AFTERNOON/EVENING
HOURS ACROSS THE PLAINS. STORMS ARE EXPECTED TO ONCE AGAIN PRODUCE
MVFR/IFR CONDITIONS IN MODERATE TO HEAVY RAIN...WITH SOME STORMS
POSSIBLY BECOMING STRONG OR SEVERE OVER EXTREME SOUTHEAST WYOMING
AND THE SOUTHERN PANHANDLE.

WINDS WILL RAPIDLY SHIFT INTO THE WEST LATER TONIGHT BRINGING
DRIER AIR TO THE REGION BUT ALSO THE THREAT OF STRONG GUSTY WINDS
OVER 45 KNOTS...MAINLY AFTER MIDNIGHT.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT MON SEP 29 2014

UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE FORECAST AREA
TODAY AND TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FOUND
OVER MOST OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TODAY. LESS
ACTIVITY IS EXPECTED INTO CARBON COUNTY WITH ISOLATED SHOWERS AND
THUNDERSTORMS OUTSIDE OF THE MOUNTAINS. SNOW ACCUMULATIONS LIKELY
INTO THE SNOWY AND SIERRA MADRE MOUNTAINS. STRONG WEST WINDS TO
DEVELOP TONIGHT OVER PORTIONS OF SOUTHEAST WYOMING. BREEZY TO WINDY
ACROSS THE AREA TUESDAY. COOL WEATHER WITH CHANCES FOR SHOWERS
TUESDAY AND WEDNESDAY. DRYING OUT AND WARMING UP LATE THIS WEEK AND
INTO THE WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...NONE.

&&

$$

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












000
FXUS65 KCYS 291239 CCA
AFDCYS

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE CHEYENNE WY
639 AM MDT MON SEP 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM MDT MON SEP 29 2014

AN ACTIVE DAY OF WEATHER TODAY AS UPPER LEVEL LOW PRESSURE MOVES
INTO THE CENTRAL ROCKIES. SHOWERS AND THUNDERSTORMS CURRENTLY
NOTICEABLE ON RADAR IN ASSOCIATION WITH A VORTICITY LOBE WHICH IS
LIFTING NORTHWARD AHEAD OF THE MAIN UPPER LEVEL LOW. THIS ACTIVITY
SHOULD SUBSIDE SOMEWHAT THROUGH THIS MORNING BUT SHOULD CONTINUE
TO SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN
SHOT OF SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL THIS
MID AFTERNOON AS THE MAIN UPPER LEVEL LOW LIFTS INTO SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE. THIS IS A VERY DYNAMIC SYSTEM
AND WILL BRING WITH IT THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
SNOW TO THE MOUNTAINS.

CLOUD COVER THIS AFTERNOON MAY SERVE TO SLIGHTLY LIMIT THE
OVERALL THREAT FOR SEVERE STORMS...BUT REGARDLESS OF SURFACE
HEATING...UPPER LEVEL FORCING SHOULD MORE THAN COMPENSATE. STRONG
DIFFLUENT/DIVERGENT FLOW AND COOLING ALOFT WILL PRODUCE AMPLE
LIFT AND INSTABILITY RESPECTIVELY. THE MAIN SEVERE THREATS WILL BE
HAIL AND HEAVY RAIN...BUT STRONG WIND GUSTS WILL BE POSSIBLE...AS
WELL AS...TORNADOES. LCL HEIGHTS WILL BE VERY CLOSE TO THE GROUND
SUCH THAT ANY STRONG UPDRAFTS WILL NOT HAVE TO DO MUCH WORK TO
STRETCH AND TILT HORIZONTAL VORTICITY. MODELS SOLUTIONS ARE
SHOWING SOUTHEAST SURFACE WINDS OVER FAR SOUTHEAST WYOMING AND
MUCH OF THE NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING. WINDS
ALOFT QUICKLY VEER WITH HEIGHT WHICH IS ALSO FAVORABLE FOR TORNADO
GENESIS. THE MAIN TIME FRAME FOR SEVERE THUNDERSTORMS AND TORNADO
POTENTIAL WILL BE MID AFTERNOON THROUGH MID EVENING.

40 TO 50 KTS OF EFFECTIVE BULK SHEAR ALONG WITH ELEVATED CAPE
AROUND 1000 J/KG WILL BE ENOUGH TO PRODUCE ROBUST UPDRAFTS CAPABLE
OF PRODUCING LARGE HAIL. ALTHOUGH FREEZING LEVELS ARE RATHER HIGH
FOR THIS TIME OF YEAR...THEY WILL ONLY BE 7000 TO 9000 FEET AGL BY
00Z THIS EVENING AND FALLING. THIS MEANS HAILS STONES WILL HAVE
NOT HAVE MUCH TIME TO MELT BEFORE REACHING THE GROUND. WOULD NOT
BE COMPLETELY SURPRISED TO SEE HAIL TO THE SIZE OF GOLF BALLS WITH A
FEW STORMS LATE THIS AFTERNOON AND EARLY EVENING...PARTICULARLY
INTO THE NEBRASKA PANHANDLE. ALSO WORRIED ABOUT HEAVY RAIN. DUAL
POLE RADAR ALREADY SHOWING 1 TO 2 INCHES OF RAIN WITH LAST EVENING
AND OVERNIGHT CONVECTION FOR PORTIONS OF THE AREA. HEAVY RAINS OVER
THESE AREAS LATE TODAY AND TONIGHT MAY BE ENOUGH TO PRODUCE SOME
FLASH FLOODING. FORTUNATELY IT HAS BEEN DRY AS OF LATE SO GENERALLY
THE GROUND SHOULD BE ABLE TO HANDLE HEAVY RAIN...AS LONG AS THERE
IS NOT TOO MUCH TRAINING OF STORMS...WHICH IS POSSIBLE.

THE OTHER MAIN CONCERN IS FOR LATER TONIGHT AS WESTERLY WINDS
INCREASE AND STRONG SUBSIDENCE DEVELOPS BEHIND THE UPPER LOW.
SURFACE PRESSURE GRADIENTS WILL INCREASE AS SURFACE LOW PRESSURE
DEVELOPS IN THE NORTHERN PLAINS AND COLD AIR ADVECTS EASTWARD.
THESE FACTORS WILL LEAD TO THE DEVELOPMENT OF STRONG WEST
WINDS...MAINLY IN WIND PRONE AREAS OF SOUTHEAST WYOMING. HAVE
ISSUED A HIGH WIND WARNING FOR THE WIND PRONE AREAS SUCH AS THE
SOUTHERN LARAMIE RANGE AND FOOTHILLS...ARLINGTON...AND BORDEAUX.
HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON TUESDAY.
WILL ALSO HAVE TO KEEP AN EYE ON THE NORTHERN NEBRASKA PANHANDLE
FOR WIND ADVISORY POTENTIAL.


.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON SEP 29 2014

A GOOD CHANCE OF SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE
THROUGH EARLY WEDNESDAY NIGHT AS THE LAST UPPER LEVEL TROUGH WILL
PUSH EAST OF THE AREA BY EARLY THURSDAY MORNING. THE BEST CHANCE
FOR SHOWERS WILL BE ALONG AND SOUTH OF I80 AS THE TROUGH WILL BE
RATHER PROGRESSIVE. THE HIGHER MOUNTAINS ABOVE 8500 FEET WILL SEE
SNOWFALL INTO THURSDAY MORNING WITH A FEW INCHES OF ACCUMULATION
POSSIBLE. SNOW LEVEL SHOULD REMAIN ABOVE VALLEY FLOORS...ALTHOUGH
IT MAY GET CLOSE TO THE LARAMIE VALLEY FOR A TIME LATE WEDNESDAY
NIGHT. ALL MODELS IN AGREEMENT LATE NEXT WEEK SHOWING STRONG
NORTHWEST FLOW ALOFT RESULTING IN COOL TEMPERATURES FOR THURSDAY
AND FRIDAY...BUT DRIER CONDITIONS ARE EXPECTED AS THE POLAR JET
STREAM SHIFTS NORTHWARD INTO CANADA. TEMPERATURES ON THURSDAY WILL
REMAIN BELOW AVERAGE WITH HIGHS IN THE 50S TO MID 60S.

ALL MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED...SHOWING NORTHWEST
FLOW ALOFT CONTINUING INTO NEXT WEEK. HOWEVER...TEMPERATURES WILL
GRADUALLY INCREASE WITH HIGHS LIKELY AROUND 70 BY SATURDAY AND
SUNDAY AFTERNOON AS A RIDGE AXIS BUILDS ALONG THE WEST COAST AND
THEN DRIFTS EASTWARD. KEPT POP BELOW 10 PERCENT EACH DAY.


&&

.AVIATION...(FOR THE 12Z TAFS THROUGH MONDAY NIGHT)
ISSUED AT 420 AM MDT MON SEP 29 2014

SCATTERED SHOWERS AND TSTORMS WILL CONTINUE THIS MORNING ACROSS
THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS A STRONG STORM SYSTEM
SLOWLY MOVES EASTWARD INTO THE ROCKY MOUNTAINS. BETWEEN THE
INDIVIDUAL TSTORM CELLS...AREAS OF FOG AND LOW STRATUS WILL
PERSIST THROUGH SUNRISE WITH IFR CONDITIONS EXPECTED. CONDITIONS
WILL SLOWLY IMPROVE LATER THIS MORNING...WITH LIGHT RAIN/DRIZZLE
CONTINUING OVER MOST EASTERN SITES THROUGH LATE MORNING. THIS
BRIEF LULL IN THE ACTION WILL NOT LAST LONG HOWEVER...AS
CONVECTION WILL RAPIDLY REDEVELOP OVER THE MOUNTAINS IN THE EARLY
AFTERNOON AND WILL MOVE NORTHEAST THROUGH THE AFTERNOON/EVENING
HOURS ACROSS THE PLAINS. STORMS ARE EXPECTED TO ONCE AGAIN PRODUCE
MVFR/IFR CONDITIONS IN MODERATE TO HEAVY RAIN...WITH SOME STORMS
POSSIBLY BECOMING STRONG OR SEVERE OVER EXTREME SOUTHEAST WYOMING
AND THE SOUTHERN PANHANDLE.

WINDS WILL RAPIDLY SHIFT INTO THE WEST LATER TONIGHT BRINGING
DRIER AIR TO THE REGION BUT ALSO THE THREAT OF STRONG GUSTY WINDS
OVER 45 KNOTS...MAINLY AFTER MIDNIGHT.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT MON SEP 29 2014

UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE FORECAST AREA
TODAY AND TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FOUND
OVER MOST OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TODAY. LESS
ACTIVITY IS EXPECTED INTO CARBON COUNTY WITH ISOLATED SHOWERS AND
THUNDERSTORMS OUTSIDE OF THE MOUNTAINS. SNOW ACCUMULATIONS LIKELY
INTO THE SNOWY AND SIERRA MADRE MOUNTAINS. STRONG WEST WINDS TO
DEVELOP TONIGHT OVER PORTIONS OF SOUTHEAST WYOMING. BREEZY TO WINDY
ACROSS THE AREA TUESDAY. COOL WEATHER WITH CHANCES FOR SHOWERS
TUESDAY AND WEDNESDAY. DRYING OUT AND WARMING UP LATE THIS WEEK AND
INTO THE WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...NONE.

&&

$$

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













000
FXUS65 KCYS 291056
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
456 AM MDT MON SEP 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM MDT MON SEP 29 2014

AN ACTIVE DAY OF WEATHER TODAY AS UPPER LEVEL LOW PRESSURE MOVES
INTO THE CENTRAL ROCKIES. SHOWERS AND THUNDERSTORMS CURRENTLY
NOTICEABLE ON RADAR IN ASSOCIATION WITH A VORTICITY LOBE WHICH IS
LIFTING NORTHWARD AHEAD OF THE MAIN UPPER LEVEL LOW. THIS ACTIVITY
SHOULD SUBSIDE SOMEWHAT THROUGH THIS MORNING BUT SHOULD CONTINUE
TO SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN
SHOT OF SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL THIS
MID AFTERNOON AS THE MAIN UPPER LEVEL LOW LIFTS INTO SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE. THIS IS A VERY DYNAMIC SYSTEM
AND WILL BRING WITH IT THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
SNOW TO THE MOUNTAINS.

CLOUD COVER THIS AFTERNOON MAY SERVE TO SLIGHTLY LIMIT THE
OVERALL THREAT FOR SEVERE STORMS...BUT REGARDLESS OF SURFACE
HEATING...UPPER LEVEL FORCING SHOULD MORE THAN COMPENSATE. STRONG
DIFFLUENT/DIVERGENT FLOW AND COOLING ALOFT WILL PRODUCE AMPLE
LIFT AND INSTABILITY RESPECTIVELY. THE MAIN SEVERE THREATS WILL BE
HAIL AND HEAVY RAIN...BUT STRONG WIND GUSTS WILL BE POSSIBLE...AS
WELL AS...TORNADOES. LCL HEIGHTS WILL BE VERY CLOSE TO THE GROUND
SUCH THAT ANY STRONG UPDRAFTS WILL NOT HAVE TO DO MUCH WORK TO
STRETCH AND TILT HORIZONTAL VORTICITY. MODELS SOLUTIONS ARE
SHOWING SOUTHEAST SURFACE WINDS OVER FAR SOUTHEAST WYOMING AND
MUCH OF THE NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING. WINDS
ALOFT QUICKLY VEER WITH HEIGHT WHICH IS ALSO FAVORABLE FOR TORNADO
GENESIS. THE MAIN TIME FRAME FOR SEVERE THUNDERSTORMS AND TORNADO
POTENTIAL WILL BE MID AFTERNOON THROUGH MID EVENING.

40 TO 50 KTS OF EFFECTIVE BULK SHEAR ALONG WITH ELEVATED CAPE
AROUND 1000 J/KG WILL BE ENOUGH TO PRODUCE ROBUST UPDRAFTS CAPABLE
OF PRODUCING LARGE HAIL. ALTHOUGH FREEZING LEVELS ARE RATHER HIGH
FOR THIS TIME OF YEAR...THEY WILL ONLY BE 7000 TO 9000 FEET AGL BY
00Z THIS EVENING AND FALLING. THIS MEANS HAILS STONES WILL HAVE
NOT HAVE MUCH TIME TO MELT BEFORE REACHING THE GROUND. WOULD NOT
BE COMPLETELY SURPRISED TO SEE HAIL TO THE SIZE OF GOLF BALLS WITH A
FEW STORMS LATE THIS AFTERNOON AND EARLY EVENING...PARTICULARLY
INTO THE NEBRASKA PANHANDLE. ALSO WORRIED ABOUT HEAVY RAIN. DUAL
POLE RADAR ALREADY SHOWING 1 TO 2 INCHES OF RAIN WITH LAST EVENING
AND OVERNIGHT CONVECTION FOR PORTIONS OF THE AREA. EVEN SEEING
AROUND 3 INCHES NEAR HARRISBURG IN BANNER COUNTY. HEAVY RAINS OVER
THESE AREAS LATE TODAY AND TONIGHT MAY BE ENOUGH TO PRODUCE SOME
FLASH FLOODING. FORTUNATELY IT HAS BEEN DRY AS OF LATE SO
GENERALLY THE GROUND SHOULD BE ABLE TO HANDLE SOME HEAVY
RAINS...AS LONG AS THERE IS NOT TOO MUCH TRAINING OF
STORMS...WHICH IS POSSIBLE.

THE OTHER MAIN CONCERN IS FOR LATER TONIGHT AS WESTERLY WINDS
INCREASE AND STRONG SUBSIDENCE DEVELOPS BEHIND THE UPPER LOW.
SURFACE PRESSURE GRADIENTS WILL INCREASE AS SURFACE LOW PRESSURE
DEVELOPS IN THE NORTHERN PLAINS AND COLD AIR ADVECTS EASTWARD.
THESE FACTORS WILL LEAD TO THE DEVELOPMENT OF STRONG WEST
WINDS...MAINLY IN WIND PRONE AREAS OF SOUTHEAST WYOMING. HAVE
ISSUED A HIGH WIND WARNING FOR THE WIND PRONE AREAS SUCH AS THE
SOUTHERN LARAMIE RANGE AND FOOTHILLS...ARLINGTON...AND BORDEAUX.
HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON TUESDAY.
WILL ALSO HAVE TO KEEP AN EYE ON THE NORTHERN NEBRASKA PANHANDLE
FOR WIND ADVISORY POTENTIAL.


.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON SEP 29 2014

A GOOD CHANCE OF SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE
THROUGH EARLY WEDNESDAY NIGHT AS THE LAST UPPER LEVEL TROUGH WILL
PUSH EAST OF THE AREA BY EARLY THURSDAY MORNING. THE BEST CHANCE
FOR SHOWERS WILL BE ALONG AND SOUTH OF I80 AS THE TROUGH WILL BE
RATHER PROGRESSIVE. THE HIGHER MOUNTAINS ABOVE 8500 FEET WILL SEE
SNOWFALL INTO THURSDAY MORNING WITH A FEW INCHES OF ACCUMULATION
POSSIBLE. SNOW LEVEL SHOULD REMAIN ABOVE VALLEY FLOORS...ALTHOUGH
IT MAY GET CLOSE TO THE LARAMIE VALLEY FOR A TIME LATE WEDNESDAY
NIGHT. ALL MODELS IN AGREEMENT LATE NEXT WEEK SHOWING STRONG
NORTHWEST FLOW ALOFT RESULTING IN COOL TEMPERATURES FOR THURSDAY
AND FRIDAY...BUT DRIER CONDITIONS ARE EXPECTED AS THE POLAR JET
STREAM SHIFTS NORTHWARD INTO CANADA. TEMPERATURES ON THURSDAY WILL
REMAIN BELOW AVERAGE WITH HIGHS IN THE 50S TO MID 60S.

ALL MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED...SHOWING NORTHWEST
FLOW ALOFT CONTINUING INTO NEXT WEEK. HOWEVER...TEMPERATURES WILL
GRADUALLY INCREASE WITH HIGHS LIKELY AROUND 70 BY SATURDAY AND
SUNDAY AFTERNOON AS A RIDGE AXIS BUILDS ALONG THE WEST COAST AND
THEN DRIFTS EASTWARD. KEPT POP BELOW 10 PERCENT EACH DAY.


&&

.AVIATION...(FOR THE 12Z TAFS THROUGH MONDAY NIGHT)

SCATTERED SHOWERS AND TSTORMS WILL CONTINUE THIS MORNING ACROSS
THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS A STRONG STORM SYSTEM
SLOWLY MOVES EASTWARD INTO THE ROCKY MOUNTAINS. BETWEEN THE
INDIVIDUAL TSTORM CELLS...AREAS OF FOG AND LOW STRATUS WILL
PERSIST THROUGH SUNRISE WITH IFR CONDITIONS EXPECTED. CONDITIONS
WILL SLOWLY IMPROVE LATER THIS MORNING...WITH LIGHT RAIN/DRIZZLE
CONTINUING OVER MOST EASTERN SITES THROUGH LATE MORNING. THIS
BRIEF LULL IN THE ACTION WILL NOT LAST LONG HOWEVER...AS
CONVECTION WILL RAPIDLY REDEVELOP OVER THE MOUNTAINS IN THE EARLY
AFTERNOON AND WILL MOVE NORTHEAST THROUGH THE AFTERNOON/EVENING
HOURS ACROSS THE PLAINS. STORMS ARE EXPECTED TO ONCE AGAIN PRODUCE
MVFR/IFR CONDITIONS IN MODERATE TO HEAVY RAIN...WITH SOME STORMS
POSSIBLY BECOMING STRONG OR SEVERE OVER EXTREME SOUTHEAST WYOMING
AND THE SOUTHERN PANHANDLE.

WINDS WILL RAPIDLY SHIFT INTO THE WEST LATER TONIGHT BRINGING
DRIER AIR TO THE REGION BUT ALSO THE THREAT OF STRONG GUSTY WINDS
OVER 45 KNOTS...MAINLY AFTER MIDNIGHT.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT MON SEP 29 2014

UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE FORECAST AREA
TODAY AND TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FOUND
OVER MOST OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TODAY. LESS
ACTIVITY IS EXPECTED INTO CARBON COUNTY WITH ISOLATED SHOWERS AND
THUNDERSTORMS OUTSIDE OF THE MOUNTAINS. SNOW ACCUMULATIONS LIKELY
INTO THE SNOWY AND SIERRA MADRE MOUNTAINS. STRONG WEST WINDS TO
DEVELOP TONIGHT OVER PORTIONS OF SOUTHEAST WYOMING. BREEZY TO WINDY
ACROSS THE AREA TUESDAY. COOL WEATHER WITH CHANCES FOR SHOWERS
TUESDAY AND WEDNESDAY. DRYING OUT AND WARMING UP LATE THIS WEEK AND
INTO THE WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...NONE.

&&

$$

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









000
FXUS65 KCYS 291056
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
456 AM MDT MON SEP 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM MDT MON SEP 29 2014

AN ACTIVE DAY OF WEATHER TODAY AS UPPER LEVEL LOW PRESSURE MOVES
INTO THE CENTRAL ROCKIES. SHOWERS AND THUNDERSTORMS CURRENTLY
NOTICEABLE ON RADAR IN ASSOCIATION WITH A VORTICITY LOBE WHICH IS
LIFTING NORTHWARD AHEAD OF THE MAIN UPPER LEVEL LOW. THIS ACTIVITY
SHOULD SUBSIDE SOMEWHAT THROUGH THIS MORNING BUT SHOULD CONTINUE
TO SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THE MAIN
SHOT OF SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL THIS
MID AFTERNOON AS THE MAIN UPPER LEVEL LOW LIFTS INTO SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE. THIS IS A VERY DYNAMIC SYSTEM
AND WILL BRING WITH IT THE POTENTIAL FOR SEVERE THUNDERSTORMS AND
SNOW TO THE MOUNTAINS.

CLOUD COVER THIS AFTERNOON MAY SERVE TO SLIGHTLY LIMIT THE
OVERALL THREAT FOR SEVERE STORMS...BUT REGARDLESS OF SURFACE
HEATING...UPPER LEVEL FORCING SHOULD MORE THAN COMPENSATE. STRONG
DIFFLUENT/DIVERGENT FLOW AND COOLING ALOFT WILL PRODUCE AMPLE
LIFT AND INSTABILITY RESPECTIVELY. THE MAIN SEVERE THREATS WILL BE
HAIL AND HEAVY RAIN...BUT STRONG WIND GUSTS WILL BE POSSIBLE...AS
WELL AS...TORNADOES. LCL HEIGHTS WILL BE VERY CLOSE TO THE GROUND
SUCH THAT ANY STRONG UPDRAFTS WILL NOT HAVE TO DO MUCH WORK TO
STRETCH AND TILT HORIZONTAL VORTICITY. MODELS SOLUTIONS ARE
SHOWING SOUTHEAST SURFACE WINDS OVER FAR SOUTHEAST WYOMING AND
MUCH OF THE NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING. WINDS
ALOFT QUICKLY VEER WITH HEIGHT WHICH IS ALSO FAVORABLE FOR TORNADO
GENESIS. THE MAIN TIME FRAME FOR SEVERE THUNDERSTORMS AND TORNADO
POTENTIAL WILL BE MID AFTERNOON THROUGH MID EVENING.

40 TO 50 KTS OF EFFECTIVE BULK SHEAR ALONG WITH ELEVATED CAPE
AROUND 1000 J/KG WILL BE ENOUGH TO PRODUCE ROBUST UPDRAFTS CAPABLE
OF PRODUCING LARGE HAIL. ALTHOUGH FREEZING LEVELS ARE RATHER HIGH
FOR THIS TIME OF YEAR...THEY WILL ONLY BE 7000 TO 9000 FEET AGL BY
00Z THIS EVENING AND FALLING. THIS MEANS HAILS STONES WILL HAVE
NOT HAVE MUCH TIME TO MELT BEFORE REACHING THE GROUND. WOULD NOT
BE COMPLETELY SURPRISED TO SEE HAIL TO THE SIZE OF GOLF BALLS WITH A
FEW STORMS LATE THIS AFTERNOON AND EARLY EVENING...PARTICULARLY
INTO THE NEBRASKA PANHANDLE. ALSO WORRIED ABOUT HEAVY RAIN. DUAL
POLE RADAR ALREADY SHOWING 1 TO 2 INCHES OF RAIN WITH LAST EVENING
AND OVERNIGHT CONVECTION FOR PORTIONS OF THE AREA. EVEN SEEING
AROUND 3 INCHES NEAR HARRISBURG IN BANNER COUNTY. HEAVY RAINS OVER
THESE AREAS LATE TODAY AND TONIGHT MAY BE ENOUGH TO PRODUCE SOME
FLASH FLOODING. FORTUNATELY IT HAS BEEN DRY AS OF LATE SO
GENERALLY THE GROUND SHOULD BE ABLE TO HANDLE SOME HEAVY
RAINS...AS LONG AS THERE IS NOT TOO MUCH TRAINING OF
STORMS...WHICH IS POSSIBLE.

THE OTHER MAIN CONCERN IS FOR LATER TONIGHT AS WESTERLY WINDS
INCREASE AND STRONG SUBSIDENCE DEVELOPS BEHIND THE UPPER LOW.
SURFACE PRESSURE GRADIENTS WILL INCREASE AS SURFACE LOW PRESSURE
DEVELOPS IN THE NORTHERN PLAINS AND COLD AIR ADVECTS EASTWARD.
THESE FACTORS WILL LEAD TO THE DEVELOPMENT OF STRONG WEST
WINDS...MAINLY IN WIND PRONE AREAS OF SOUTHEAST WYOMING. HAVE
ISSUED A HIGH WIND WARNING FOR THE WIND PRONE AREAS SUCH AS THE
SOUTHERN LARAMIE RANGE AND FOOTHILLS...ARLINGTON...AND BORDEAUX.
HIGH WIND WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON TUESDAY.
WILL ALSO HAVE TO KEEP AN EYE ON THE NORTHERN NEBRASKA PANHANDLE
FOR WIND ADVISORY POTENTIAL.


.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON SEP 29 2014

A GOOD CHANCE OF SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE
THROUGH EARLY WEDNESDAY NIGHT AS THE LAST UPPER LEVEL TROUGH WILL
PUSH EAST OF THE AREA BY EARLY THURSDAY MORNING. THE BEST CHANCE
FOR SHOWERS WILL BE ALONG AND SOUTH OF I80 AS THE TROUGH WILL BE
RATHER PROGRESSIVE. THE HIGHER MOUNTAINS ABOVE 8500 FEET WILL SEE
SNOWFALL INTO THURSDAY MORNING WITH A FEW INCHES OF ACCUMULATION
POSSIBLE. SNOW LEVEL SHOULD REMAIN ABOVE VALLEY FLOORS...ALTHOUGH
IT MAY GET CLOSE TO THE LARAMIE VALLEY FOR A TIME LATE WEDNESDAY
NIGHT. ALL MODELS IN AGREEMENT LATE NEXT WEEK SHOWING STRONG
NORTHWEST FLOW ALOFT RESULTING IN COOL TEMPERATURES FOR THURSDAY
AND FRIDAY...BUT DRIER CONDITIONS ARE EXPECTED AS THE POLAR JET
STREAM SHIFTS NORTHWARD INTO CANADA. TEMPERATURES ON THURSDAY WILL
REMAIN BELOW AVERAGE WITH HIGHS IN THE 50S TO MID 60S.

ALL MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED...SHOWING NORTHWEST
FLOW ALOFT CONTINUING INTO NEXT WEEK. HOWEVER...TEMPERATURES WILL
GRADUALLY INCREASE WITH HIGHS LIKELY AROUND 70 BY SATURDAY AND
SUNDAY AFTERNOON AS A RIDGE AXIS BUILDS ALONG THE WEST COAST AND
THEN DRIFTS EASTWARD. KEPT POP BELOW 10 PERCENT EACH DAY.


&&

.AVIATION...(FOR THE 12Z TAFS THROUGH MONDAY NIGHT)

SCATTERED SHOWERS AND TSTORMS WILL CONTINUE THIS MORNING ACROSS
THE HIGH PLAINS EAST OF THE LARAMIE RANGE AS A STRONG STORM SYSTEM
SLOWLY MOVES EASTWARD INTO THE ROCKY MOUNTAINS. BETWEEN THE
INDIVIDUAL TSTORM CELLS...AREAS OF FOG AND LOW STRATUS WILL
PERSIST THROUGH SUNRISE WITH IFR CONDITIONS EXPECTED. CONDITIONS
WILL SLOWLY IMPROVE LATER THIS MORNING...WITH LIGHT RAIN/DRIZZLE
CONTINUING OVER MOST EASTERN SITES THROUGH LATE MORNING. THIS
BRIEF LULL IN THE ACTION WILL NOT LAST LONG HOWEVER...AS
CONVECTION WILL RAPIDLY REDEVELOP OVER THE MOUNTAINS IN THE EARLY
AFTERNOON AND WILL MOVE NORTHEAST THROUGH THE AFTERNOON/EVENING
HOURS ACROSS THE PLAINS. STORMS ARE EXPECTED TO ONCE AGAIN PRODUCE
MVFR/IFR CONDITIONS IN MODERATE TO HEAVY RAIN...WITH SOME STORMS
POSSIBLY BECOMING STRONG OR SEVERE OVER EXTREME SOUTHEAST WYOMING
AND THE SOUTHERN PANHANDLE.

WINDS WILL RAPIDLY SHIFT INTO THE WEST LATER TONIGHT BRINGING
DRIER AIR TO THE REGION BUT ALSO THE THREAT OF STRONG GUSTY WINDS
OVER 45 KNOTS...MAINLY AFTER MIDNIGHT.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT MON SEP 29 2014

UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE FORECAST AREA
TODAY AND TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FOUND
OVER MOST OF SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TODAY. LESS
ACTIVITY IS EXPECTED INTO CARBON COUNTY WITH ISOLATED SHOWERS AND
THUNDERSTORMS OUTSIDE OF THE MOUNTAINS. SNOW ACCUMULATIONS LIKELY
INTO THE SNOWY AND SIERRA MADRE MOUNTAINS. STRONG WEST WINDS TO
DEVELOP TONIGHT OVER PORTIONS OF SOUTHEAST WYOMING. BREEZY TO WINDY
ACROSS THE AREA TUESDAY. COOL WEATHER WITH CHANCES FOR SHOWERS
TUESDAY AND WEDNESDAY. DRYING OUT AND WARMING UP LATE THIS WEEK AND
INTO THE WEEKEND.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR
     WYZ106-110-116-117.

NE...NONE.

&&

$$

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










000
FXUS65 KCYS 290624
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1224 AM MDT MON SEP 29 2014

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 311 PM MDT SUN SEP 28 2014

AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH MOST OF THE SHORT
TERM FCST PERIOD. WATER VAPOR SATELLITE SHOWS AN IMPRESSIVE UPPER
LOW MOVING SLOWLY EASTWARD ACROSS CENTRAL NV THIS AFTN. VERY MOIST
AIR MASS AHEAD OF THIS SYSTEM OVER WESTERN CO IS ADVECTING NORTH
INTO OUR SOUTHWEST ZONES AS OF 21Z WITH SHOWERS AND EMBEDDED TSTMS
INCREASING IN COVERAGE OVER CARBON AND WESTERN ALBANY COUNTIES. IT
STILL APPEARS THAT UPPER-LEVEL DIFFLUENCE WILL BECOME QUITE STRONG
THIS EVE AND OVERNIGHT AS THE AFORMENTIONED SYSTEM ROLLS INTO THE
FOUR CORNERS REGION AND A 100 KT JET STREAK ROUNDS THE BASE OF THE
TROUGH OVER EASTERN UT. MAIN THREAT FROM SHOWERS AND TSTMS TONIGHT
WILL BE LOCALLY HEAVY RAIN AS UPSTREAM AM SOUNDINGS AND NEAR-TERM
MODELS SHOW PWATS WELL IN EXCESS OF 1 INCH AND EXCELLENT MOISTURE
TRANSPORT IN THE LLVLS. DEEP SATURATION ON VARIOUS BUFKIT PROFILES
WOULD ALSO SUPPORT THIS...SO MENTIONED HEAVY RAIN THRU THE NIGHT
WHERE PCPN SHOULD BE MOST NUMEROUS. STILL SOME CONCERN FOR STRONG
TO SEVERE CONVECTION ALONG THE I-80 CORRIDOR EAST OF CHEYENNE IN
ZONE OF STRONGER DIURNAL HEATING...BUT BECOMING LESS LIKELY WITH
LITTLE VERTICAL CU GROWTH AND DYNAMICS LAGGING TO THE W. IF STORMS
CAN GET GOING BY LATE AFTN OR EARLY EVE...AROUND 1000 J/KG MUCAPES
AND 40-50 KTS OF EFFECTIVE BULK SHEAR WOULD SUPPORT ISOLATED LARGE
HAIL. INCREASED LOWS TONIGHT IN ANTICIPATION OF WIDESPREAD CLOUDS
AND PCPN.

COMPACT SHORTWAVE EJECTS NORTHEAST OVER THE FRONT RANGE ON MON AS
ANOTHER MIDLVL SHORTWAVE DIVES INTO THE PAC NW. MOIST LLVL UPSLOPE
CONTINUES OVER THE EASTERN PLAINS...SUPPORTING STRATIFORM RAIN AND
EMBEDDED TSTMS THROUGH THE DAY. GFS/NAM/EC SHOW SIGNIFICANT SFC
CYCLOGENESIS BY LATE MON NIGHT WITH A 990-995 MB LOW THE NORTHEAST
OF OUR CWA. EXCELLENT QG ASCENT ON THE BACK SIDE OF THIS SYSTEM
AND GOOD MOISTURE SHOULD PROVE SUPPORTIVE OF A PERIOD OF VERY
HEAVY RAIN. LATER SHIFTS MAY WANT TO CONSIDER A FLASH FLOOD WATCH
FOR PARTS OF SOUTHEAST WY AND THE PANHANDLE. HOWEVER...700-300 HPA
MOISTURE PROGS DRY OUT RATHER QUICKLY OVERNIGHT WHICH COULD LIMIT
OVERALL QPF AMOUNTS. GFS SHOWS H7 TEMPS FALLING TO BETWEEN -1C AND
1C OVER THE SNOWIES AND SIERRA MADRES DURING THIS TIME...SO COULD
SEE A FEW INCHES OF SUB-ADVISORY SNOWS THERE. MOST OF THE DYNAMICS
WILL BE WELL TO THE EAST BY THEN...SO DO NOT EXPECT MAJOR MOUNTAIN
ACCUMULATIONS. GROWING CONCERNS FOR SEVERE TSTMS ON MON AFTN. THE
LATEST SPC DAY 2 OUTLOOK PLACES MUCH OF THE PANHANDLE IN A SLIGHT
RISK. GFS AND NAM ARE IN GOOD AGREEMENT WITH UP TO 1500 J/KG OF
SBCAPE AND LIS AROUND -5C. SHEAR PROFILES WILL BE RATHER STRONG AS
WELL BENEATH AROUND 40 KTS OF H5 FLOW. MAIN QUESTION RIGHT NOW IS
WHETHER WE WILL HAVE ENOUGH SUNSHINE TO REALIZE INSTABILITY. HELD
OFF ON MENTION OF SEVERE IN THE GRIDS FOR NOW.

WEST WINDS ARE SET TO INCREASE CONSIDERABLY BY TUE AM AS THE LOW
LIFTS OUT. GFS SHOWS A POCKET OF 750 MILLIBAR WINDS AS HIGH AS 70
KTS AT 12Z TUE FROM THE LARAMIE RANGE EASTWARD INTO CYS. BEST
SUBSIDENCE MAY REMAIN TO THE SOUTH...AND WINDS ALOFT ARE FCST TO
DECREASE PRIOR TO AFTN MIXING. EVEN SO...WE COULD SEE OUR FIRST
HIGH WIND EVENT OF THE SEASON AS THE H85 CAG-CPR GRADIENT
INCREASES TO AROUND 60 METERS. LATER SHIFTS WILL NEED TO MONITOR
FOR A POSSIBLE HIGH WIND WATCH FOR AT LEAST THE WIND PRONE AREAS
AS WE GET CLOSER TO THE EVENT. LOOK FOR PCPN TO SLOWLY DECREASE IN
COVERAGE FROM SOUTHWEST TO NORTHEAST ON TUE.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 311 PM MDT SUN SEP 28 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE WED-THU WITH DRIER CONDITIONS
BENEATH BUILDING HEIGHTS FOR FRI-SUN. INITIALLY...POSITIVELY TILTED
SHORTWAVE ENERGY WILL BE ACROSS MONTANA/IDAHO. THIS SHORTWAVE WILL
SLIDE SOUTHEAST INTO THE CWFA LATE WEDNESDAY AND WEDNESDAY NIGHT
PROVIDING THE BEST OPPORTUNITY FOR PRECIPITATION THROUGH THE PERIOD.
PROGD FREEZING LEVELS HOVER AROUND 10 KFT...WHICH WOULD SUGGEST
ACTUALLY SNOW-LEVELS SHOULD END UP BEING AROUND 9500 FEET. A COUPLE
OF INCHES OF SNOW ACCUMULATIONS WILL CERTAINLY BE A POSSIBILITY
ABOVE THIS LEVEL. TEMPERATURES WILL AGAIN BE BELOW AVERAGE ON
WEDNESDAY WITH H7 TEMPERATURES PROGD TO BE AROUND 2C. HIGH
TEMPERATURES WILL ONLY REACH THE 50S...WITH PERHAPS A FEW LOW 60S IN
LOWEST ELEVATIONS. 12Z MODELS HAVE TRENDED TOWARDS THE MORE
PROGRESSIVE 00Z ECMWF WITH THURSDAYS CLIPPER SYSTEM. ASIDE FROM A
BRIEF REINFORCING SHOT OF COOLER AIR...EXPECT LITTLE IMPACT FROM
THIS SYSTEM. DESPITE THE BRIEF LLVL CAA...BETTER INSOLATION ON BOTH
THU-FRI SHOULD ALLOW HIGHS TO CLIMB BACK INTO THE 60S IN ALL LOWER
ELEVATIONS. BOTH THE ECMWF/GFS MAINTAIN THE DRY AND WARMING TREND
INTO SAT-SUN WITH H7 PROGS CLIMBING BACK TO 7-8C. HIGH TEMPERATURES
BOTH DAY SHOULD BE CLOSE TO 70F WEST OF THE LARAMIE RANGE...WITH 70S
EAST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1224 AM MDT MON SEP 29 2014

SHOWERS AND STORMS CONTINUE AT 06Z OVER THE NORTHERN AND EASTERN
NEBRASKA SITES...AND OVER THE MOUNTAINS AND HIGH VALLEY SITES OF
SOUTHEAST WYOMING. EXPECT THIS ACTIVITY TO CONTINUE MOVING NORTH
AND EAST THRU THE NIGHT...WITH A STRATUS DECK LOOKING FAIRLY WELL
ENTRENCHED OVER MOST OF THE CWA AS WELL. AREAS OF FOG WILL OCCUR
VCTY LARAMIE RANGE IN BETWEEN SHOWERS...WITH IFR/LIFR VSBYS
EXPECTED. CONDITIONS WILL BE SLOW TO IMPROVE THRU THE
MORNING...WITH LIGHT RAIN/DRIZZLE CONTINUING OVER MOST EASTERN SITES
THRU LATE MORNING. CONVECTION WILL REDEVELOP OVER THE MOUNTAINS IN
THE EARLY AFTERNOON AND WILL TREK NORTHEAST THRU THE
AFTERNOON/EVENING ACROSS THE PLAINS. STORMS ARE EXPECTED TO ONCE
AGAIN PRODUCE MVFR/IFR CONDITIONS IN MODERATE TO HEAVY RAIN...WITH
SOME STORMS POSSIBLY BECOMING SEVERE IN THE SOUTHERN PANHANDLE
THRU THE EVENING.

&&

.FIRE WEATHER...
ISSUED AT 311 PM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS. A COOLER AND UNSETTLED WEATHER PATTERN
WILL RESULT IN HUMIDITIES WELL ABOVE CRITICAL THRESHOLDS. SHOWER
AND THUNDERSTORM ACTIVITY WILL BE WIDESPREAD OVER THE NEXT 24 TO
36 HOURS...WITH UP TO A HALF INCH OF RAIN POSSIBLE FOR MANY AREAS
ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE. WINDY CONDITIONS
ARE LIKELY FOR TUESDAY.

&&

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

$$

SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...RJM
FIRE WEATHER...HAMMER







000
FXUS65 KCYS 290624
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1224 AM MDT MON SEP 29 2014

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 311 PM MDT SUN SEP 28 2014

AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH MOST OF THE SHORT
TERM FCST PERIOD. WATER VAPOR SATELLITE SHOWS AN IMPRESSIVE UPPER
LOW MOVING SLOWLY EASTWARD ACROSS CENTRAL NV THIS AFTN. VERY MOIST
AIR MASS AHEAD OF THIS SYSTEM OVER WESTERN CO IS ADVECTING NORTH
INTO OUR SOUTHWEST ZONES AS OF 21Z WITH SHOWERS AND EMBEDDED TSTMS
INCREASING IN COVERAGE OVER CARBON AND WESTERN ALBANY COUNTIES. IT
STILL APPEARS THAT UPPER-LEVEL DIFFLUENCE WILL BECOME QUITE STRONG
THIS EVE AND OVERNIGHT AS THE AFORMENTIONED SYSTEM ROLLS INTO THE
FOUR CORNERS REGION AND A 100 KT JET STREAK ROUNDS THE BASE OF THE
TROUGH OVER EASTERN UT. MAIN THREAT FROM SHOWERS AND TSTMS TONIGHT
WILL BE LOCALLY HEAVY RAIN AS UPSTREAM AM SOUNDINGS AND NEAR-TERM
MODELS SHOW PWATS WELL IN EXCESS OF 1 INCH AND EXCELLENT MOISTURE
TRANSPORT IN THE LLVLS. DEEP SATURATION ON VARIOUS BUFKIT PROFILES
WOULD ALSO SUPPORT THIS...SO MENTIONED HEAVY RAIN THRU THE NIGHT
WHERE PCPN SHOULD BE MOST NUMEROUS. STILL SOME CONCERN FOR STRONG
TO SEVERE CONVECTION ALONG THE I-80 CORRIDOR EAST OF CHEYENNE IN
ZONE OF STRONGER DIURNAL HEATING...BUT BECOMING LESS LIKELY WITH
LITTLE VERTICAL CU GROWTH AND DYNAMICS LAGGING TO THE W. IF STORMS
CAN GET GOING BY LATE AFTN OR EARLY EVE...AROUND 1000 J/KG MUCAPES
AND 40-50 KTS OF EFFECTIVE BULK SHEAR WOULD SUPPORT ISOLATED LARGE
HAIL. INCREASED LOWS TONIGHT IN ANTICIPATION OF WIDESPREAD CLOUDS
AND PCPN.

COMPACT SHORTWAVE EJECTS NORTHEAST OVER THE FRONT RANGE ON MON AS
ANOTHER MIDLVL SHORTWAVE DIVES INTO THE PAC NW. MOIST LLVL UPSLOPE
CONTINUES OVER THE EASTERN PLAINS...SUPPORTING STRATIFORM RAIN AND
EMBEDDED TSTMS THROUGH THE DAY. GFS/NAM/EC SHOW SIGNIFICANT SFC
CYCLOGENESIS BY LATE MON NIGHT WITH A 990-995 MB LOW THE NORTHEAST
OF OUR CWA. EXCELLENT QG ASCENT ON THE BACK SIDE OF THIS SYSTEM
AND GOOD MOISTURE SHOULD PROVE SUPPORTIVE OF A PERIOD OF VERY
HEAVY RAIN. LATER SHIFTS MAY WANT TO CONSIDER A FLASH FLOOD WATCH
FOR PARTS OF SOUTHEAST WY AND THE PANHANDLE. HOWEVER...700-300 HPA
MOISTURE PROGS DRY OUT RATHER QUICKLY OVERNIGHT WHICH COULD LIMIT
OVERALL QPF AMOUNTS. GFS SHOWS H7 TEMPS FALLING TO BETWEEN -1C AND
1C OVER THE SNOWIES AND SIERRA MADRES DURING THIS TIME...SO COULD
SEE A FEW INCHES OF SUB-ADVISORY SNOWS THERE. MOST OF THE DYNAMICS
WILL BE WELL TO THE EAST BY THEN...SO DO NOT EXPECT MAJOR MOUNTAIN
ACCUMULATIONS. GROWING CONCERNS FOR SEVERE TSTMS ON MON AFTN. THE
LATEST SPC DAY 2 OUTLOOK PLACES MUCH OF THE PANHANDLE IN A SLIGHT
RISK. GFS AND NAM ARE IN GOOD AGREEMENT WITH UP TO 1500 J/KG OF
SBCAPE AND LIS AROUND -5C. SHEAR PROFILES WILL BE RATHER STRONG AS
WELL BENEATH AROUND 40 KTS OF H5 FLOW. MAIN QUESTION RIGHT NOW IS
WHETHER WE WILL HAVE ENOUGH SUNSHINE TO REALIZE INSTABILITY. HELD
OFF ON MENTION OF SEVERE IN THE GRIDS FOR NOW.

WEST WINDS ARE SET TO INCREASE CONSIDERABLY BY TUE AM AS THE LOW
LIFTS OUT. GFS SHOWS A POCKET OF 750 MILLIBAR WINDS AS HIGH AS 70
KTS AT 12Z TUE FROM THE LARAMIE RANGE EASTWARD INTO CYS. BEST
SUBSIDENCE MAY REMAIN TO THE SOUTH...AND WINDS ALOFT ARE FCST TO
DECREASE PRIOR TO AFTN MIXING. EVEN SO...WE COULD SEE OUR FIRST
HIGH WIND EVENT OF THE SEASON AS THE H85 CAG-CPR GRADIENT
INCREASES TO AROUND 60 METERS. LATER SHIFTS WILL NEED TO MONITOR
FOR A POSSIBLE HIGH WIND WATCH FOR AT LEAST THE WIND PRONE AREAS
AS WE GET CLOSER TO THE EVENT. LOOK FOR PCPN TO SLOWLY DECREASE IN
COVERAGE FROM SOUTHWEST TO NORTHEAST ON TUE.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 311 PM MDT SUN SEP 28 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE WED-THU WITH DRIER CONDITIONS
BENEATH BUILDING HEIGHTS FOR FRI-SUN. INITIALLY...POSITIVELY TILTED
SHORTWAVE ENERGY WILL BE ACROSS MONTANA/IDAHO. THIS SHORTWAVE WILL
SLIDE SOUTHEAST INTO THE CWFA LATE WEDNESDAY AND WEDNESDAY NIGHT
PROVIDING THE BEST OPPORTUNITY FOR PRECIPITATION THROUGH THE PERIOD.
PROGD FREEZING LEVELS HOVER AROUND 10 KFT...WHICH WOULD SUGGEST
ACTUALLY SNOW-LEVELS SHOULD END UP BEING AROUND 9500 FEET. A COUPLE
OF INCHES OF SNOW ACCUMULATIONS WILL CERTAINLY BE A POSSIBILITY
ABOVE THIS LEVEL. TEMPERATURES WILL AGAIN BE BELOW AVERAGE ON
WEDNESDAY WITH H7 TEMPERATURES PROGD TO BE AROUND 2C. HIGH
TEMPERATURES WILL ONLY REACH THE 50S...WITH PERHAPS A FEW LOW 60S IN
LOWEST ELEVATIONS. 12Z MODELS HAVE TRENDED TOWARDS THE MORE
PROGRESSIVE 00Z ECMWF WITH THURSDAYS CLIPPER SYSTEM. ASIDE FROM A
BRIEF REINFORCING SHOT OF COOLER AIR...EXPECT LITTLE IMPACT FROM
THIS SYSTEM. DESPITE THE BRIEF LLVL CAA...BETTER INSOLATION ON BOTH
THU-FRI SHOULD ALLOW HIGHS TO CLIMB BACK INTO THE 60S IN ALL LOWER
ELEVATIONS. BOTH THE ECMWF/GFS MAINTAIN THE DRY AND WARMING TREND
INTO SAT-SUN WITH H7 PROGS CLIMBING BACK TO 7-8C. HIGH TEMPERATURES
BOTH DAY SHOULD BE CLOSE TO 70F WEST OF THE LARAMIE RANGE...WITH 70S
EAST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1224 AM MDT MON SEP 29 2014

SHOWERS AND STORMS CONTINUE AT 06Z OVER THE NORTHERN AND EASTERN
NEBRASKA SITES...AND OVER THE MOUNTAINS AND HIGH VALLEY SITES OF
SOUTHEAST WYOMING. EXPECT THIS ACTIVITY TO CONTINUE MOVING NORTH
AND EAST THRU THE NIGHT...WITH A STRATUS DECK LOOKING FAIRLY WELL
ENTRENCHED OVER MOST OF THE CWA AS WELL. AREAS OF FOG WILL OCCUR
VCTY LARAMIE RANGE IN BETWEEN SHOWERS...WITH IFR/LIFR VSBYS
EXPECTED. CONDITIONS WILL BE SLOW TO IMPROVE THRU THE
MORNING...WITH LIGHT RAIN/DRIZZLE CONTINUING OVER MOST EASTERN SITES
THRU LATE MORNING. CONVECTION WILL REDEVELOP OVER THE MOUNTAINS IN
THE EARLY AFTERNOON AND WILL TREK NORTHEAST THRU THE
AFTERNOON/EVENING ACROSS THE PLAINS. STORMS ARE EXPECTED TO ONCE
AGAIN PRODUCE MVFR/IFR CONDITIONS IN MODERATE TO HEAVY RAIN...WITH
SOME STORMS POSSIBLY BECOMING SEVERE IN THE SOUTHERN PANHANDLE
THRU THE EVENING.

&&

.FIRE WEATHER...
ISSUED AT 311 PM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS. A COOLER AND UNSETTLED WEATHER PATTERN
WILL RESULT IN HUMIDITIES WELL ABOVE CRITICAL THRESHOLDS. SHOWER
AND THUNDERSTORM ACTIVITY WILL BE WIDESPREAD OVER THE NEXT 24 TO
36 HOURS...WITH UP TO A HALF INCH OF RAIN POSSIBLE FOR MANY AREAS
ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE. WINDY CONDITIONS
ARE LIKELY FOR TUESDAY.

&&

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

$$

SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...RJM
FIRE WEATHER...HAMMER








000
FXUS65 KCYS 290111
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
711 PM MDT SUN SEP 28 2014

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 311 PM MDT SUN SEP 28 2014

AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH MOST OF THE SHORT
TERM FCST PERIOD. WATER VAPOR SATELLITE SHOWS AN IMPRESSIVE UPPER
LOW MOVING SLOWLY EASTWARD ACROSS CENTRAL NV THIS AFTN. VERY MOIST
AIR MASS AHEAD OF THIS SYSTEM OVER WESTERN CO IS ADVECTING NORTH
INTO OUR SOUTHWEST ZONES AS OF 21Z WITH SHOWERS AND EMBEDDED TSTMS
INCREASING IN COVERAGE OVER CARBON AND WESTERN ALBANY COUNTIES. IT
STILL APPEARS THAT UPPER-LEVEL DIFFLUENCE WILL BECOME QUITE STRONG
THIS EVE AND OVERNIGHT AS THE AFORMENTIONED SYSTEM ROLLS INTO THE
FOUR CORNERS REGION AND A 100 KT JET STREAK ROUNDS THE BASE OF THE
TROUGH OVER EASTERN UT. MAIN THREAT FROM SHOWERS AND TSTMS TONIGHT
WILL BE LOCALLY HEAVY RAIN AS UPSTREAM AM SOUNDINGS AND NEAR-TERM
MODELS SHOW PWATS WELL IN EXCESS OF 1 INCH AND EXCELLENT MOISTURE
TRANSPORT IN THE LLVLS. DEEP SATURATION ON VARIOUS BUFKIT PROFILES
WOULD ALSO SUPPORT THIS...SO MENTIONED HEAVY RAIN THRU THE NIGHT
WHERE PCPN SHOULD BE MOST NUMEROUS. STILL SOME CONCERN FOR STRONG
TO SEVERE CONVECTION ALONG THE I-80 CORRIDOR EAST OF CHEYENNE IN
ZONE OF STRONGER DIURNAL HEATING...BUT BECOMING LESS LIKELY WITH
LITTLE VERTICAL CU GROWTH AND DYNAMICS LAGGING TO THE W. IF STORMS
CAN GET GOING BY LATE AFTN OR EARLY EVE...AROUND 1000 J/KG MUCAPES
AND 40-50 KTS OF EFFECTIVE BULK SHEAR WOULD SUPPORT ISOLATED LARGE
HAIL. INCREASED LOWS TONIGHT IN ANTICIPATION OF WIDESPREAD CLOUDS
AND PCPN.

COMPACT SHORTWAVE EJECTS NORTHEAST OVER THE FRONT RANGE ON MON AS
ANOTHER MIDLVL SHORTWAVE DIVES INTO THE PAC NW. MOIST LLVL UPSLOPE
CONTINUES OVER THE EASTERN PLAINS...SUPPORTING STRATIFORM RAIN AND
EMBEDDED TSTMS THROUGH THE DAY. GFS/NAM/EC SHOW SIGNIFICANT SFC
CYCLOGENESIS BY LATE MON NIGHT WITH A 990-995 MB LOW THE NORTHEAST
OF OUR CWA. EXCELLENT QG ASCENT ON THE BACK SIDE OF THIS SYSTEM
AND GOOD MOISTURE SHOULD PROVE SUPPORTIVE OF A PERIOD OF VERY
HEAVY RAIN. LATER SHIFTS MAY WANT TO CONSIDER A FLASH FLOOD WATCH
FOR PARTS OF SOUTHEAST WY AND THE PANHANDLE. HOWEVER...700-300 HPA
MOISTURE PROGS DRY OUT RATHER QUICKLY OVERNIGHT WHICH COULD LIMIT
OVERALL QPF AMOUNTS. GFS SHOWS H7 TEMPS FALLING TO BETWEEN -1C AND
1C OVER THE SNOWIES AND SIERRA MADRES DURING THIS TIME...SO COULD
SEE A FEW INCHES OF SUB-ADVISORY SNOWS THERE. MOST OF THE DYNAMICS
WILL BE WELL TO THE EAST BY THEN...SO DO NOT EXPECT MAJOR MOUNTAIN
ACCUMULATIONS. GROWING CONCERNS FOR SEVERE TSTMS ON MON AFTN. THE
LATEST SPC DAY 2 OUTLOOK PLACES MUCH OF THE PANHANDLE IN A SLIGHT
RISK. GFS AND NAM ARE IN GOOD AGREEMENT WITH UP TO 1500 J/KG OF
SBCAPE AND LIS AROUND -5C. SHEAR PROFILES WILL BE RATHER STRONG AS
WELL BENEATH AROUND 40 KTS OF H5 FLOW. MAIN QUESTION RIGHT NOW IS
WHETHER WE WILL HAVE ENOUGH SUNSHINE TO REALIZE INSTABILITY. HELD
OFF ON MENTION OF SEVERE IN THE GRIDS FOR NOW.

WEST WINDS ARE SET TO INCREASE CONSIDERABLY BY TUE AM AS THE LOW
LIFTS OUT. GFS SHOWS A POCKET OF 750 MILLIBAR WINDS AS HIGH AS 70
KTS AT 12Z TUE FROM THE LARAMIE RANGE EASTWARD INTO CYS. BEST
SUBSIDENCE MAY REMAIN TO THE SOUTH...AND WINDS ALOFT ARE FCST TO
DECREASE PRIOR TO AFTN MIXING. EVEN SO...WE COULD SEE OUR FIRST
HIGH WIND EVENT OF THE SEASON AS THE H85 CAG-CPR GRADIENT
INCREASES TO AROUND 60 METERS. LATER SHIFTS WILL NEED TO MONITOR
FOR A POSSIBLE HIGH WIND WATCH FOR AT LEAST THE WIND PRONE AREAS
AS WE GET CLOSER TO THE EVENT. LOOK FOR PCPN TO SLOWLY DECREASE IN
COVERAGE FROM SOUTHWEST TO NORTHEAST ON TUE.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 311 PM MDT SUN SEP 28 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE WED-THU WITH DRIER CONDITIONS
BENEATH BUILDING HEIGHTS FOR FRI-SUN. INITIALLY...POSITIVELY TILTED
SHORTWAVE ENERGY WILL BE ACROSS MONTANA/IDAHO. THIS SHORTWAVE WILL
SLIDE SOUTHEAST INTO THE CWFA LATE WEDNESDAY AND WEDNESDAY NIGHT
PROVIDING THE BEST OPPORTUNITY FOR PRECIPITATION THROUGH THE PERIOD.
PROGD FREEZING LEVELS HOVER AROUND 10 KFT...WHICH WOULD SUGGEST
ACTUALLY SNOW-LEVELS SHOULD END UP BEING AROUND 9500 FEET. A COUPLE
OF INCHES OF SNOW ACCUMULATIONS WILL CERTAINLY BE A POSSIBILITY
ABOVE THIS LEVEL. TEMPERATURES WILL AGAIN BE BELOW AVERAGE ON
WEDNESDAY WITH H7 TEMPERATURES PROGD TO BE AROUND 2C. HIGH
TEMPERATURES WILL ONLY REACH THE 50S...WITH PERHAPS A FEW LOW 60S IN
LOWEST ELEVATIONS. 12Z MODELS HAVE TRENDED TOWARDS THE MORE
PROGRESSIVE 00Z ECMWF WITH THURSDAYS CLIPPER SYSTEM. ASIDE FROM A
BRIEF REINFORCING SHOT OF COOLER AIR...EXPECT LITTLE IMPACT FROM
THIS SYSTEM. DESPITE THE BRIEF LLVL CAA...BETTER INSOLATION ON BOTH
THU-FRI SHOULD ALLOW HIGHS TO CLIMB BACK INTO THE 60S IN ALL LOWER
ELEVATIONS. BOTH THE ECMWF/GFS MAINTAIN THE DRY AND WARMING TREND
INTO SAT-SUN WITH H7 PROGS CLIMBING BACK TO 7-8C. HIGH TEMPERATURES
BOTH DAY SHOULD BE CLOSE TO 70F WEST OF THE LARAMIE RANGE...WITH 70S
EAST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY AFTERNOON)
ISSUED AT 710 PM MDT SUN SEP 28 2014

A LINE OF SHOWERS AND T-STORMS MOVING NORTH TO NORTHEAST ACROSS THE
EASTERN PLAINS THIS EVENING AND OVERNIGHT WILL BRING LIFR TO MVFR
CONDITIONS TO THE TERMINALS IN MODERATE TO HEAVY RAIN. ADDITIONAL
SHOWERS AND STORMS WILL REDEVELOP OVER THE MOUNTAINS OF SOUTHEAST
WYOMING AFTER 04Z AND WILL IMPACT WESTERN TERMINALS DURING THE
OVERNIGHT HOURS. GUIDANCE SHOWS A BRIEF BREAK IN PRECIP MONDAY
MORNING...WITH AREAS OF FOG/STRATUS SETTLING IN DURING THIS TIME.
ANOTHER ROUND OF CONVECTION WILL DEVELOP OVER THE FORECAST AREA
MONDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 311 PM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS. A COOLER AND UNSETTLED WEATHER PATTERN
WILL RESULT IN HUMIDITIES WELL ABOVE CRITICAL THRESHOLDS. SHOWER
AND THUNDERSTORM ACTIVITY WILL BE WIDESPREAD OVER THE NEXT 24 TO
36 HOURS...WITH UP TO A HALF INCH OF RAIN POSSIBLE FOR MANY AREAS
ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE. WINDY CONDITIONS
ARE LIKELY FOR TUESDAY.

&&

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

$$

SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...RJM
FIRE WEATHER...HAMMER







000
FXUS65 KCYS 290111
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
711 PM MDT SUN SEP 28 2014

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 311 PM MDT SUN SEP 28 2014

AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH MOST OF THE SHORT
TERM FCST PERIOD. WATER VAPOR SATELLITE SHOWS AN IMPRESSIVE UPPER
LOW MOVING SLOWLY EASTWARD ACROSS CENTRAL NV THIS AFTN. VERY MOIST
AIR MASS AHEAD OF THIS SYSTEM OVER WESTERN CO IS ADVECTING NORTH
INTO OUR SOUTHWEST ZONES AS OF 21Z WITH SHOWERS AND EMBEDDED TSTMS
INCREASING IN COVERAGE OVER CARBON AND WESTERN ALBANY COUNTIES. IT
STILL APPEARS THAT UPPER-LEVEL DIFFLUENCE WILL BECOME QUITE STRONG
THIS EVE AND OVERNIGHT AS THE AFORMENTIONED SYSTEM ROLLS INTO THE
FOUR CORNERS REGION AND A 100 KT JET STREAK ROUNDS THE BASE OF THE
TROUGH OVER EASTERN UT. MAIN THREAT FROM SHOWERS AND TSTMS TONIGHT
WILL BE LOCALLY HEAVY RAIN AS UPSTREAM AM SOUNDINGS AND NEAR-TERM
MODELS SHOW PWATS WELL IN EXCESS OF 1 INCH AND EXCELLENT MOISTURE
TRANSPORT IN THE LLVLS. DEEP SATURATION ON VARIOUS BUFKIT PROFILES
WOULD ALSO SUPPORT THIS...SO MENTIONED HEAVY RAIN THRU THE NIGHT
WHERE PCPN SHOULD BE MOST NUMEROUS. STILL SOME CONCERN FOR STRONG
TO SEVERE CONVECTION ALONG THE I-80 CORRIDOR EAST OF CHEYENNE IN
ZONE OF STRONGER DIURNAL HEATING...BUT BECOMING LESS LIKELY WITH
LITTLE VERTICAL CU GROWTH AND DYNAMICS LAGGING TO THE W. IF STORMS
CAN GET GOING BY LATE AFTN OR EARLY EVE...AROUND 1000 J/KG MUCAPES
AND 40-50 KTS OF EFFECTIVE BULK SHEAR WOULD SUPPORT ISOLATED LARGE
HAIL. INCREASED LOWS TONIGHT IN ANTICIPATION OF WIDESPREAD CLOUDS
AND PCPN.

COMPACT SHORTWAVE EJECTS NORTHEAST OVER THE FRONT RANGE ON MON AS
ANOTHER MIDLVL SHORTWAVE DIVES INTO THE PAC NW. MOIST LLVL UPSLOPE
CONTINUES OVER THE EASTERN PLAINS...SUPPORTING STRATIFORM RAIN AND
EMBEDDED TSTMS THROUGH THE DAY. GFS/NAM/EC SHOW SIGNIFICANT SFC
CYCLOGENESIS BY LATE MON NIGHT WITH A 990-995 MB LOW THE NORTHEAST
OF OUR CWA. EXCELLENT QG ASCENT ON THE BACK SIDE OF THIS SYSTEM
AND GOOD MOISTURE SHOULD PROVE SUPPORTIVE OF A PERIOD OF VERY
HEAVY RAIN. LATER SHIFTS MAY WANT TO CONSIDER A FLASH FLOOD WATCH
FOR PARTS OF SOUTHEAST WY AND THE PANHANDLE. HOWEVER...700-300 HPA
MOISTURE PROGS DRY OUT RATHER QUICKLY OVERNIGHT WHICH COULD LIMIT
OVERALL QPF AMOUNTS. GFS SHOWS H7 TEMPS FALLING TO BETWEEN -1C AND
1C OVER THE SNOWIES AND SIERRA MADRES DURING THIS TIME...SO COULD
SEE A FEW INCHES OF SUB-ADVISORY SNOWS THERE. MOST OF THE DYNAMICS
WILL BE WELL TO THE EAST BY THEN...SO DO NOT EXPECT MAJOR MOUNTAIN
ACCUMULATIONS. GROWING CONCERNS FOR SEVERE TSTMS ON MON AFTN. THE
LATEST SPC DAY 2 OUTLOOK PLACES MUCH OF THE PANHANDLE IN A SLIGHT
RISK. GFS AND NAM ARE IN GOOD AGREEMENT WITH UP TO 1500 J/KG OF
SBCAPE AND LIS AROUND -5C. SHEAR PROFILES WILL BE RATHER STRONG AS
WELL BENEATH AROUND 40 KTS OF H5 FLOW. MAIN QUESTION RIGHT NOW IS
WHETHER WE WILL HAVE ENOUGH SUNSHINE TO REALIZE INSTABILITY. HELD
OFF ON MENTION OF SEVERE IN THE GRIDS FOR NOW.

WEST WINDS ARE SET TO INCREASE CONSIDERABLY BY TUE AM AS THE LOW
LIFTS OUT. GFS SHOWS A POCKET OF 750 MILLIBAR WINDS AS HIGH AS 70
KTS AT 12Z TUE FROM THE LARAMIE RANGE EASTWARD INTO CYS. BEST
SUBSIDENCE MAY REMAIN TO THE SOUTH...AND WINDS ALOFT ARE FCST TO
DECREASE PRIOR TO AFTN MIXING. EVEN SO...WE COULD SEE OUR FIRST
HIGH WIND EVENT OF THE SEASON AS THE H85 CAG-CPR GRADIENT
INCREASES TO AROUND 60 METERS. LATER SHIFTS WILL NEED TO MONITOR
FOR A POSSIBLE HIGH WIND WATCH FOR AT LEAST THE WIND PRONE AREAS
AS WE GET CLOSER TO THE EVENT. LOOK FOR PCPN TO SLOWLY DECREASE IN
COVERAGE FROM SOUTHWEST TO NORTHEAST ON TUE.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 311 PM MDT SUN SEP 28 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE WED-THU WITH DRIER CONDITIONS
BENEATH BUILDING HEIGHTS FOR FRI-SUN. INITIALLY...POSITIVELY TILTED
SHORTWAVE ENERGY WILL BE ACROSS MONTANA/IDAHO. THIS SHORTWAVE WILL
SLIDE SOUTHEAST INTO THE CWFA LATE WEDNESDAY AND WEDNESDAY NIGHT
PROVIDING THE BEST OPPORTUNITY FOR PRECIPITATION THROUGH THE PERIOD.
PROGD FREEZING LEVELS HOVER AROUND 10 KFT...WHICH WOULD SUGGEST
ACTUALLY SNOW-LEVELS SHOULD END UP BEING AROUND 9500 FEET. A COUPLE
OF INCHES OF SNOW ACCUMULATIONS WILL CERTAINLY BE A POSSIBILITY
ABOVE THIS LEVEL. TEMPERATURES WILL AGAIN BE BELOW AVERAGE ON
WEDNESDAY WITH H7 TEMPERATURES PROGD TO BE AROUND 2C. HIGH
TEMPERATURES WILL ONLY REACH THE 50S...WITH PERHAPS A FEW LOW 60S IN
LOWEST ELEVATIONS. 12Z MODELS HAVE TRENDED TOWARDS THE MORE
PROGRESSIVE 00Z ECMWF WITH THURSDAYS CLIPPER SYSTEM. ASIDE FROM A
BRIEF REINFORCING SHOT OF COOLER AIR...EXPECT LITTLE IMPACT FROM
THIS SYSTEM. DESPITE THE BRIEF LLVL CAA...BETTER INSOLATION ON BOTH
THU-FRI SHOULD ALLOW HIGHS TO CLIMB BACK INTO THE 60S IN ALL LOWER
ELEVATIONS. BOTH THE ECMWF/GFS MAINTAIN THE DRY AND WARMING TREND
INTO SAT-SUN WITH H7 PROGS CLIMBING BACK TO 7-8C. HIGH TEMPERATURES
BOTH DAY SHOULD BE CLOSE TO 70F WEST OF THE LARAMIE RANGE...WITH 70S
EAST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY AFTERNOON)
ISSUED AT 710 PM MDT SUN SEP 28 2014

A LINE OF SHOWERS AND T-STORMS MOVING NORTH TO NORTHEAST ACROSS THE
EASTERN PLAINS THIS EVENING AND OVERNIGHT WILL BRING LIFR TO MVFR
CONDITIONS TO THE TERMINALS IN MODERATE TO HEAVY RAIN. ADDITIONAL
SHOWERS AND STORMS WILL REDEVELOP OVER THE MOUNTAINS OF SOUTHEAST
WYOMING AFTER 04Z AND WILL IMPACT WESTERN TERMINALS DURING THE
OVERNIGHT HOURS. GUIDANCE SHOWS A BRIEF BREAK IN PRECIP MONDAY
MORNING...WITH AREAS OF FOG/STRATUS SETTLING IN DURING THIS TIME.
ANOTHER ROUND OF CONVECTION WILL DEVELOP OVER THE FORECAST AREA
MONDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 311 PM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS. A COOLER AND UNSETTLED WEATHER PATTERN
WILL RESULT IN HUMIDITIES WELL ABOVE CRITICAL THRESHOLDS. SHOWER
AND THUNDERSTORM ACTIVITY WILL BE WIDESPREAD OVER THE NEXT 24 TO
36 HOURS...WITH UP TO A HALF INCH OF RAIN POSSIBLE FOR MANY AREAS
ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE. WINDY CONDITIONS
ARE LIKELY FOR TUESDAY.

&&

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

$$

SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...RJM
FIRE WEATHER...HAMMER








000
FXUS65 KCYS 282212
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
412 PM MDT SUN SEP 28 2014

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 311 PM MDT SUN SEP 28 2014

AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH MOST OF THE SHORT
TERM FCST PERIOD. WATER VAPOR SATELLITE SHOWS AN IMPRESSIVE UPPER
LOW MOVING SLOWLY EASTWARD ACROSS CENTRAL NV THIS AFTN. VERY MOIST
AIR MASS AHEAD OF THIS SYSTEM OVER WESTERN CO IS ADVECTING NORTH
INTO OUR SOUTHWEST ZONES AS OF 21Z WITH SHOWERS AND EMBEDDED TSTMS
INCREASING IN COVERAGE OVER CARBON AND WESTERN ALBANY COUNTIES. IT
STILL APPEARS THAT UPPER-LEVEL DIFFLUENCE WILL BECOME QUITE STRONG
THIS EVE AND OVERNIGHT AS THE AFORMENTIONED SYSTEM ROLLS INTO THE
FOUR CORNERS REGION AND A 100 KT JET STREAK ROUNDS THE BASE OF THE
TROUGH OVER EASTERN UT. MAIN THREAT FROM SHOWERS AND TSTMS TONIGHT
WILL BE LOCALLY HEAVY RAIN AS UPSTREAM AM SOUNDINGS AND NEAR-TERM
MODELS SHOW PWATS WELL IN EXCESS OF 1 INCH AND EXCELLENT MOISTURE
TRANSPORT IN THE LLVLS. DEEP SATURATION ON VARIOUS BUFKIT PROFILES
WOULD ALSO SUPPORT THIS...SO MENTIONED HEAVY RAIN THRU THE NIGHT
WHERE PCPN SHOULD BE MOST NUMEROUS. STILL SOME CONCERN FOR STRONG
TO SEVERE CONVECTION ALONG THE I-80 CORRIDOR EAST OF CHEYENNE IN
ZONE OF STRONGER DIURNAL HEATING...BUT BECOMING LESS LIKELY WITH
LITTLE VERTICAL CU GROWTH AND DYNAMICS LAGGING TO THE W. IF STORMS
CAN GET GOING BY LATE AFTN OR EARLY EVE...AROUND 1000 J/KG MUCAPES
AND 40-50 KTS OF EFFECTIVE BULK SHEAR WOULD SUPPORT ISOLATED LARGE
HAIL. INCREASED LOWS TONIGHT IN ANTICIPATION OF WIDESPREAD CLOUDS
AND PCPN.

COMPACT SHORTWAVE EJECTS NORTHEAST OVER THE FRONT RANGE ON MON AS
ANOTHER MIDLVL SHORTWAVE DIVES INTO THE PAC NW. MOIST LLVL UPSLOPE
CONTINUES OVER THE EASTERN PLAINS...SUPPORTING STRATIFORM RAIN AND
EMBEDDED TSTMS THROUGH THE DAY. GFS/NAM/EC SHOW SIGNIFICANT SFC
CYCLOGENESIS BY LATE MON NIGHT WITH A 990-995 MB LOW THE NORTHEAST
OF OUR CWA. EXCELLENT QG ASCENT ON THE BACK SIDE OF THIS SYSTEM
AND GOOD MOISTURE SHOULD PROVE SUPPORTIVE OF A PERIOD OF VERY
HEAVY RAIN. LATER SHIFTS MAY WANT TO CONSIDER A FLASH FLOOD WATCH
FOR PARTS OF SOUTHEAST WY AND THE PANHANDLE. HOWEVER...700-300 HPA
MOISTURE PROGS DRY OUT RATHER QUICKLY OVERNIGHT WHICH COULD LIMIT
OVERALL QPF AMOUNTS. GFS SHOWS H7 TEMPS FALLING TO BETWEEN -1C AND
1C OVER THE SNOWIES AND SIERRA MADRES DURING THIS TIME...SO COULD
SEE A FEW INCHES OF SUB-ADVISORY SNOWS THERE. MOST OF THE DYNAMICS
WILL BE WELL TO THE EAST BY THEN...SO DO NOT EXPECT MAJOR MOUNTAIN
ACCUMULATIONS. GROWING CONCERNS FOR SEVERE TSTMS ON MON AFTN. THE
LATEST SPC DAY 2 OUTLOOK PLACES MUCH OF THE PANHANDLE IN A SLIGHT
RISK. GFS AND NAM ARE IN GOOD AGREEMENT WITH UP TO 1500 J/KG OF
SBCAPE AND LIS AROUND -5C. SHEAR PROFILES WILL BE RATHER STRONG AS
WELL BENEATH AROUND 40 KTS OF H5 FLOW. MAIN QUESTION RIGHT NOW IS
WHETHER WE WILL HAVE ENOUGH SUNSHINE TO REALIZE INSTABILITY. HELD
OFF ON MENTION OF SEVERE IN THE GRIDS FOR NOW.

WEST WINDS ARE SET TO INCREASE CONSIDERABLY BY TUE AM AS THE LOW
LIFTS OUT. GFS SHOWS A POCKET OF 750 MILLIBAR WINDS AS HIGH AS 70
KTS AT 12Z TUE FROM THE LARAMIE RANGE EASTWARD INTO CYS. BEST
SUBSIDENCE MAY REMAIN TO THE SOUTH...AND WINDS ALOFT ARE FCST TO
DECREASE PRIOR TO AFTN MIXING. EVEN SO...WE COULD SEE OUR FIRST
HIGH WIND EVENT OF THE SEASON AS THE H85 CAG-CPR GRADIENT
INCREASES TO AROUND 60 METERS. LATER SHIFTS WILL NEED TO MONITOR
FOR A POSSIBLE HIGH WIND WATCH FOR AT LEAST THE WIND PRONE AREAS
AS WE GET CLOSER TO THE EVENT. LOOK FOR PCPN TO SLOWLY DECREASE IN
COVERAGE FROM SOUTHWEST TO NORTHEAST ON TUE.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 311 PM MDT SUN SEP 28 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE WED-THU WITH DRIER CONDITIONS
BENEATH BUILDING HEIGHTS FOR FRI-SUN. INITIALLY...POSITIVELY TILTED
SHORTWAVE ENERGY WILL BE ACROSS MONTANA/IDAHO. THIS SHORTWAVE WILL
SLIDE SOUTHEAST INTO THE CWFA LATE WEDNESDAY AND WEDNESDAY NIGHT
PROVIDING THE BEST OPPORTUNITY FOR PRECIPITATION THROUGH THE PERIOD.
PROGD FREEZING LEVELS HOVER AROUND 10 KFT...WHICH WOULD SUGGEST
ACTUALLY SNOW-LEVELS SHOULD END UP BEING AROUND 9500 FEET. A COUPLE
OF INCHES OF SNOW ACCUMULATIONS WILL CERTAINLY BE A POSSIBILITY
ABOVE THIS LEVEL. TEMPERATURES WILL AGAIN BE BELOW AVERAGE ON
WEDNESDAY WITH H7 TEMPERATURES PROGD TO BE AROUND 2C. HIGH
TEMPERATURES WILL ONLY REACH THE 50S...WITH PERHAPS A FEW LOW 60S IN
LOWEST ELEVATIONS. 12Z MODELS HAVE TRENDED TOWARDS THE MORE
PROGRESSIVE 00Z ECMWF WITH THURSDAYS CLIPPER SYSTEM. ASIDE FROM A
BRIEF REINFORCING SHOT OF COOLER AIR...EXPECT LITTLE IMPACT FROM
THIS SYSTEM. DESPITE THE BRIEF LLVL CAA...BETTER INSOLATION ON BOTH
THU-FRI SHOULD ALLOW HIGHS TO CLIMB BACK INTO THE 60S IN ALL LOWER
ELEVATIONS. BOTH THE ECMWF/GFS MAINTAIN THE DRY AND WARMING TREND
INTO SAT-SUN WITH H7 PROGS CLIMBING BACK TO 7-8C. HIGH TEMPERATURES
BOTH DAY SHOULD BE CLOSE TO 70F WEST OF THE LARAMIE RANGE...WITH 70S
EAST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1200 PM MDT SUN SEP 28 2014

CHALLENGES ARE MANY FOR THIS TAF FORECAST...INITIALLY TRYING TO
TIME A LINE OF CONVECTION LIFTING NORTH AND EAST ACROSS SE WYOMING
AND THE WRN NEBRASKA PANHANDLE...THEN TRYING TO TIME ITS DEPARTURE
AND RESIDUAL LOW CLOUD/FOG POTENTIAL LATE TONIGHT AND EARLY
MONDAY. BAND OF PRECIP IS JUST NOW BEGINNING TO LIFT NORTH ACROSS
CARBON COUNTY...WITH NO IMPACT AT KRWL JUST YET. THIS WILL CHANGE
THRU 20Z HOWEVER...AS DETERIORATING CONDITIONS ARE EXPECTED THERE.
THIS PRECIP BAND WILL THEN ACCELERATE EAST IMPACTING KLAR AFTER
21Z AND KCYS MOSTLY AFTER 00Z. AREAS EAST INTO THE PANHANDLE WILL
HAVE TO WAIT UNTIL THIS EVENING TO BE IMPACTED BY THIS AREA OF
CONVECTION. THIS AREA OF SHOWERS WILL SPREAD EAST THROUGH MONDAY
MORNING...GRADUALLY BRINGING AN END TO PRECIPITATION CHANCES FROM
WEST TO EAST. HAVE GENERALLY BOTTOMED CONDITIONS OUT IN MOST
PLACES AT MVFR/IFR. MOUNTAINS WILL BE OBSCURED AS WELL THRU MUCH
OF THE PERIOD IMPACTING ROUTES ACROSS SE WYOMING.

&&

.FIRE WEATHER...
ISSUED AT 311 PM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS. A COOLER AND UNSETTLED WEATHER PATTERN
WILL RESULT IN HUMIDITIES WELL ABOVE CRITICAL THRESHOLDS. SHOWER
AND THUNDERSTORM ACTIVITY WILL BE WIDESPREAD OVER THE NEXT 24 TO
36 HOURS...WITH UP TO A HALF INCH OF RAIN POSSIBLE FOR MANY AREAS
ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE. WINDY CONDITIONS
ARE LIKELY FOR TUESDAY.

&&

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

$$

SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...HAHN
FIRE WEATHER...HAMMER








000
FXUS65 KCYS 282212
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
412 PM MDT SUN SEP 28 2014

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 311 PM MDT SUN SEP 28 2014

AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH MOST OF THE SHORT
TERM FCST PERIOD. WATER VAPOR SATELLITE SHOWS AN IMPRESSIVE UPPER
LOW MOVING SLOWLY EASTWARD ACROSS CENTRAL NV THIS AFTN. VERY MOIST
AIR MASS AHEAD OF THIS SYSTEM OVER WESTERN CO IS ADVECTING NORTH
INTO OUR SOUTHWEST ZONES AS OF 21Z WITH SHOWERS AND EMBEDDED TSTMS
INCREASING IN COVERAGE OVER CARBON AND WESTERN ALBANY COUNTIES. IT
STILL APPEARS THAT UPPER-LEVEL DIFFLUENCE WILL BECOME QUITE STRONG
THIS EVE AND OVERNIGHT AS THE AFORMENTIONED SYSTEM ROLLS INTO THE
FOUR CORNERS REGION AND A 100 KT JET STREAK ROUNDS THE BASE OF THE
TROUGH OVER EASTERN UT. MAIN THREAT FROM SHOWERS AND TSTMS TONIGHT
WILL BE LOCALLY HEAVY RAIN AS UPSTREAM AM SOUNDINGS AND NEAR-TERM
MODELS SHOW PWATS WELL IN EXCESS OF 1 INCH AND EXCELLENT MOISTURE
TRANSPORT IN THE LLVLS. DEEP SATURATION ON VARIOUS BUFKIT PROFILES
WOULD ALSO SUPPORT THIS...SO MENTIONED HEAVY RAIN THRU THE NIGHT
WHERE PCPN SHOULD BE MOST NUMEROUS. STILL SOME CONCERN FOR STRONG
TO SEVERE CONVECTION ALONG THE I-80 CORRIDOR EAST OF CHEYENNE IN
ZONE OF STRONGER DIURNAL HEATING...BUT BECOMING LESS LIKELY WITH
LITTLE VERTICAL CU GROWTH AND DYNAMICS LAGGING TO THE W. IF STORMS
CAN GET GOING BY LATE AFTN OR EARLY EVE...AROUND 1000 J/KG MUCAPES
AND 40-50 KTS OF EFFECTIVE BULK SHEAR WOULD SUPPORT ISOLATED LARGE
HAIL. INCREASED LOWS TONIGHT IN ANTICIPATION OF WIDESPREAD CLOUDS
AND PCPN.

COMPACT SHORTWAVE EJECTS NORTHEAST OVER THE FRONT RANGE ON MON AS
ANOTHER MIDLVL SHORTWAVE DIVES INTO THE PAC NW. MOIST LLVL UPSLOPE
CONTINUES OVER THE EASTERN PLAINS...SUPPORTING STRATIFORM RAIN AND
EMBEDDED TSTMS THROUGH THE DAY. GFS/NAM/EC SHOW SIGNIFICANT SFC
CYCLOGENESIS BY LATE MON NIGHT WITH A 990-995 MB LOW THE NORTHEAST
OF OUR CWA. EXCELLENT QG ASCENT ON THE BACK SIDE OF THIS SYSTEM
AND GOOD MOISTURE SHOULD PROVE SUPPORTIVE OF A PERIOD OF VERY
HEAVY RAIN. LATER SHIFTS MAY WANT TO CONSIDER A FLASH FLOOD WATCH
FOR PARTS OF SOUTHEAST WY AND THE PANHANDLE. HOWEVER...700-300 HPA
MOISTURE PROGS DRY OUT RATHER QUICKLY OVERNIGHT WHICH COULD LIMIT
OVERALL QPF AMOUNTS. GFS SHOWS H7 TEMPS FALLING TO BETWEEN -1C AND
1C OVER THE SNOWIES AND SIERRA MADRES DURING THIS TIME...SO COULD
SEE A FEW INCHES OF SUB-ADVISORY SNOWS THERE. MOST OF THE DYNAMICS
WILL BE WELL TO THE EAST BY THEN...SO DO NOT EXPECT MAJOR MOUNTAIN
ACCUMULATIONS. GROWING CONCERNS FOR SEVERE TSTMS ON MON AFTN. THE
LATEST SPC DAY 2 OUTLOOK PLACES MUCH OF THE PANHANDLE IN A SLIGHT
RISK. GFS AND NAM ARE IN GOOD AGREEMENT WITH UP TO 1500 J/KG OF
SBCAPE AND LIS AROUND -5C. SHEAR PROFILES WILL BE RATHER STRONG AS
WELL BENEATH AROUND 40 KTS OF H5 FLOW. MAIN QUESTION RIGHT NOW IS
WHETHER WE WILL HAVE ENOUGH SUNSHINE TO REALIZE INSTABILITY. HELD
OFF ON MENTION OF SEVERE IN THE GRIDS FOR NOW.

WEST WINDS ARE SET TO INCREASE CONSIDERABLY BY TUE AM AS THE LOW
LIFTS OUT. GFS SHOWS A POCKET OF 750 MILLIBAR WINDS AS HIGH AS 70
KTS AT 12Z TUE FROM THE LARAMIE RANGE EASTWARD INTO CYS. BEST
SUBSIDENCE MAY REMAIN TO THE SOUTH...AND WINDS ALOFT ARE FCST TO
DECREASE PRIOR TO AFTN MIXING. EVEN SO...WE COULD SEE OUR FIRST
HIGH WIND EVENT OF THE SEASON AS THE H85 CAG-CPR GRADIENT
INCREASES TO AROUND 60 METERS. LATER SHIFTS WILL NEED TO MONITOR
FOR A POSSIBLE HIGH WIND WATCH FOR AT LEAST THE WIND PRONE AREAS
AS WE GET CLOSER TO THE EVENT. LOOK FOR PCPN TO SLOWLY DECREASE IN
COVERAGE FROM SOUTHWEST TO NORTHEAST ON TUE.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 311 PM MDT SUN SEP 28 2014

ACTIVE NORTHWEST FLOW WILL CONTINUE WED-THU WITH DRIER CONDITIONS
BENEATH BUILDING HEIGHTS FOR FRI-SUN. INITIALLY...POSITIVELY TILTED
SHORTWAVE ENERGY WILL BE ACROSS MONTANA/IDAHO. THIS SHORTWAVE WILL
SLIDE SOUTHEAST INTO THE CWFA LATE WEDNESDAY AND WEDNESDAY NIGHT
PROVIDING THE BEST OPPORTUNITY FOR PRECIPITATION THROUGH THE PERIOD.
PROGD FREEZING LEVELS HOVER AROUND 10 KFT...WHICH WOULD SUGGEST
ACTUALLY SNOW-LEVELS SHOULD END UP BEING AROUND 9500 FEET. A COUPLE
OF INCHES OF SNOW ACCUMULATIONS WILL CERTAINLY BE A POSSIBILITY
ABOVE THIS LEVEL. TEMPERATURES WILL AGAIN BE BELOW AVERAGE ON
WEDNESDAY WITH H7 TEMPERATURES PROGD TO BE AROUND 2C. HIGH
TEMPERATURES WILL ONLY REACH THE 50S...WITH PERHAPS A FEW LOW 60S IN
LOWEST ELEVATIONS. 12Z MODELS HAVE TRENDED TOWARDS THE MORE
PROGRESSIVE 00Z ECMWF WITH THURSDAYS CLIPPER SYSTEM. ASIDE FROM A
BRIEF REINFORCING SHOT OF COOLER AIR...EXPECT LITTLE IMPACT FROM
THIS SYSTEM. DESPITE THE BRIEF LLVL CAA...BETTER INSOLATION ON BOTH
THU-FRI SHOULD ALLOW HIGHS TO CLIMB BACK INTO THE 60S IN ALL LOWER
ELEVATIONS. BOTH THE ECMWF/GFS MAINTAIN THE DRY AND WARMING TREND
INTO SAT-SUN WITH H7 PROGS CLIMBING BACK TO 7-8C. HIGH TEMPERATURES
BOTH DAY SHOULD BE CLOSE TO 70F WEST OF THE LARAMIE RANGE...WITH 70S
EAST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1200 PM MDT SUN SEP 28 2014

CHALLENGES ARE MANY FOR THIS TAF FORECAST...INITIALLY TRYING TO
TIME A LINE OF CONVECTION LIFTING NORTH AND EAST ACROSS SE WYOMING
AND THE WRN NEBRASKA PANHANDLE...THEN TRYING TO TIME ITS DEPARTURE
AND RESIDUAL LOW CLOUD/FOG POTENTIAL LATE TONIGHT AND EARLY
MONDAY. BAND OF PRECIP IS JUST NOW BEGINNING TO LIFT NORTH ACROSS
CARBON COUNTY...WITH NO IMPACT AT KRWL JUST YET. THIS WILL CHANGE
THRU 20Z HOWEVER...AS DETERIORATING CONDITIONS ARE EXPECTED THERE.
THIS PRECIP BAND WILL THEN ACCELERATE EAST IMPACTING KLAR AFTER
21Z AND KCYS MOSTLY AFTER 00Z. AREAS EAST INTO THE PANHANDLE WILL
HAVE TO WAIT UNTIL THIS EVENING TO BE IMPACTED BY THIS AREA OF
CONVECTION. THIS AREA OF SHOWERS WILL SPREAD EAST THROUGH MONDAY
MORNING...GRADUALLY BRINGING AN END TO PRECIPITATION CHANCES FROM
WEST TO EAST. HAVE GENERALLY BOTTOMED CONDITIONS OUT IN MOST
PLACES AT MVFR/IFR. MOUNTAINS WILL BE OBSCURED AS WELL THRU MUCH
OF THE PERIOD IMPACTING ROUTES ACROSS SE WYOMING.

&&

.FIRE WEATHER...
ISSUED AT 311 PM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS. A COOLER AND UNSETTLED WEATHER PATTERN
WILL RESULT IN HUMIDITIES WELL ABOVE CRITICAL THRESHOLDS. SHOWER
AND THUNDERSTORM ACTIVITY WILL BE WIDESPREAD OVER THE NEXT 24 TO
36 HOURS...WITH UP TO A HALF INCH OF RAIN POSSIBLE FOR MANY AREAS
ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE. WINDY CONDITIONS
ARE LIKELY FOR TUESDAY.

&&

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

$$

SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...HAHN
FIRE WEATHER...HAMMER







000
FXUS65 KCYS 281804
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1204 PM MDT SUN SEP 28 2014

.UPDATE...
ISSUED AT 950 AM MDT SUN SEP 28 2014

AN IMPRESSIVE UPPER-LEVEL LOW CONTINUES TO SPIN ALONG THE CA/NV
BORDER THIS AM. ABUNDANT MOISTURE IS STREAMING NORTHWARD AHEAD OF
THIS FEATURE WITH THE 12Z GJT SKEW-T SHOWING PWATS UPWARDS OF 1.25
INCH. THIS AIR MASS WILL GRADUALLY SHIFT NORTHEAST TODAY AS UPPER
DIFFLUENCE INCREASES OVER THE CWA...WITH PCPN EXPECTED TO INCREASE
IN COVERAGE FROM WEST TO EAST. ADDED HEAVY RAIN TO THE GRIDS THIS
AFTN WITH DEEP MOISTURE IN PLACE. SPC HAS A SEE TEXT FOR PTNL ISO
SEVERE TSTMS LATER TODAY. THIS WOULD MOST LIKELY BE A LATER SHOW
AS WE WAIT FOR BETTER DYNAMIC SUPPORT FARTHER E. THE AREA TO WATCH
WILL BE THE DIFFERENTIAL HEATING BOUNDARY ALONG A LINE FROM CYS TO
AIA. IF MARGINAL INSTABILITY CAN BE REALIZED...LLVL AND DEEP LAYER
SHEAR PROFILES ARE IMPRESSIVE AND WOULD SUPPORT ROTATING UPDRAFTS
ACROSS FAR SOUTHEAST WY. TEMPERATURES ARE THE OTHER CHALLENGE FOR
THIS AFTN. DECREASED HIGHS A COUPLE OF DEGREES WHERE LLVL USPLOPE
IS PROVIDING FUEL FOR DENSE STRATUS.

&&

.SHORT TERM...(TODAY AND TUESDAY)
ISSUED AT 329 AM MDT SUN SEP 28 2014

FORECAST OVER THE NEXT 48 TO 60 HOURS APPEARS ON TRACK AS A
STRONG UPPER LEVEL LOW WILL GRADUALLY MOVE ACROSS THE FORECAST
AREA THROUGH TUESDAY. AS EXPECTED...THE POSITION OF THE LOW
REMAINS OVER THE WESTERN GREAT BASIN REGION EARLY THIS MORNING AS
IT HAS STALLED OVER WESTERN NEVADA. MODELS STILL SHOW THIS LOW
MOVING VERY LITTLE TODAY...AND ACTUALLY RETROGRADING SLIGHTLY INTO
THIS EVENING BEFORE THE DOMINANT LOW PRESSURE CENTER ALOFT FINALLY
EJECTS EASTWARD SOMETIME LATE TONIGHT. RAIN SHOWERS OVER CARBON
COUNTY YESTERDAY HAVE SINCE DISSIPATED WITH ONLY PARTLY CLOUDY
SKIES WEST OF THE LARAMIE RANGE. HOWEVER...SHOWER ACTIVITY IS
STARTING TO REDEVELOP AND PUSH NORTHWARD OUT OF WESTERN COLORADO.
THIS ACTIVITY IS IN ADVANCE OF A 110 KNOT JET MAX IN ASSOCIATION
WITH AN UPPER LEVEL DISTURBANCE. MATTER OF FACT...TSTORMS ARE
STILL ON GOING ACROSS ARIZONA AS THIS DISTURBANCE BEGINS TO ROUND
THE BASE OF THE UPPER LEVEL LOW CENTER. SHOWERS AND ISOLATED
THUNDER WILL GRADUALLY INCREASE IN COVERAGE WEST OF THE LARAMIE
RANGE THIS MORNING...AND THEN EVENTUALLY PUSH INTO THE LARAMIE
RANGE AND ADJACENT HIGH PLAINS LATER TODAY. SHOWERS AND TSTORMS
WILL HOLD OFF UNTIL LATE THIS EVENING FOR WESTERN NEBRASKA...DUE
TO DRY AIR ALOFT AND SOME SUBSIDENCE ON THE WESTERN EDGE OF THE
UPPER LEVEL RIDGE ACROSS THE PLAINS. KEPT POP BETWEEN 60 TO 80
PERCENT ACROSS MOST OF SOUTHEAST WYOMING AND THE NORTHERN NEBRASKA
PANHANDLE THIS EVENING...WITH PROBABILITIES OVER 90 PERCENT ACROSS
THE LARAMIE RANGE. SOME SHOWERS/TSTORMS MAY CONTAIN VERY HEAVY
RAINFALL...GUSTY WINDS...AND SMALL HAIL. HIGHS TODAY WILL
GENERALLY BE 10 DEGREES COOLER COMPARED TO SATURDAY WITH READINGS
RANGING FROM THE MID TO UPPER 60S WEST OF THE LARAMIE RANGE...AND
70S TO NEAR 80 EAST OF THE LARAMIE RANGE. RAINFALL WILL GRADUALLY
DIMINISH FROM SOUTH TO NORTH LATE TONIGHT.

FOR MONDAY...THE MAIN SYSTEM WILL MOVE ACROSS THE CENTRAL ROCKY
MOUNTAINS AND IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT AND
POSSIBLY INTO TUESDAY. WILL HAVE TO CLOSELY MONITOR THIS SYSTEM
FOR THE POTENTIAL OF FLASH FLOODING AND STRONG
THUNDERSTORMS...SINCE MODELS INDICATE THE UPPER LEVEL LOW BECOMING
A NEGATIVELY TILTED OPEN WAVE AS IT MOVES EASTWARD...AND THEN SHOW
THE LOW CLOSING OFF AGAIN SOMEWHERE IN THE VICINITY OF EAST
CENTRAL WYOMING TOWARDS THE BLACK HILLS OF SOUTH DAKOTA. MODELS
SHOW A STRONG JET MAX ALOFT BECOMING TWO INDIVIDUAL JET STREAKS
OVER THE HIGH PLAINS FORMING A FAVORABLE DIFLUENT COUPLET IN
ADDITION TO RAPID LEE-SIDE CYCLOGENESIS. THERE IS THE POTENTIAL
FOR A WIDESPREAD MODERATE TO HEAVY RAINFALL EVENT ALONG WITH RAIN
CHANGING TO SNOW IN THE MOUNTAINS ABOVE 9000 FEET. AFTER A BRIEF
LULL MONDAY MORNING WITH MAINLY DRIZZLE...LOW STRATUS AND PATCHY
FOG...SHOWERS AND TSTORMS WILL QUICKLY DEVELOP AND INCREASE IN
COVERAGE DURING THE AFTERNOON. INCREASED POP BETWEEN 70 TO 90
PERCENT ACROSS MOST OF THE HIGH PLAINS ALONG AND EAST OF THE
LARAMIE RANGE. TEMPERATURES WILL BE CLOSER TO NORMAL ON MONDAY AND
GENERALLY IN THE 60S ACROSS SOUTHEAST WYOMING AND LOW TO MID 70S
ACROSS WESTERN NEBRASKA.

VERY WINDY CONDITIONS MAY BE A CONCERN FOR LATE MONDAY NIGHT AND
TUESDAY AS THE GFS INDICATES WINDS AT 700MB OVER 55 KNOTS...MAINLY
DUE TO WINDS BECOMING WESTERLY AND RAPID CYCLOGENESIS OVER THE
HIGH PLAINS AS THE SURFACE LOW FORMS OVER NE COLORADO AND MOVES
DUE NORTH ACROSS THE BLACK HILLS. A BIT TOO EARLY TO SEE HIGH WIND
CRITERIA...ALONG MODELS HINT TOWARDS DECENT LLVL SUBSIDENCE BY
EARLY TUESDAY MORNING. WILL LIKELY NEED WIND ADVISORIES FOR
PORTIONS OF WESTERN NEBRASKA ON TUESDAY. GUSTS UP TO 55 MPH ARE
POSSIBLE ACROSS THE WIND PRONE AREAS OF SOUTHEAST WYOMING...WITH
GUSTS UP TO 45 MPH ELSEWHERE. TUESDAY WILL BE SOMEWHAT DRIER DUE
TO DOWNSLOPE WINDS...BUT RAIN SHOWERS CAN NOT BE RULED
OUT...ESPECIALLY NORTH OF I80.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MDT SUN SEP 27 2014

EXTENDED MODELS IN RELATIVELY GOOD AGREEMENT THROUGH THURSDAY WITH A
MEAN UPPER LEVEL TROUGH OVER THE WESTERN AND CENTRAL CONUS. THE
DEVIL IS IN THE DETAILS WITH CHANCES FOR PRECIPITATION MAINLY
DEPENDING ON TIMING AND PLACEMENT OF SHORTWAVE ENERGY EMBEDDED IN
THE UPPER LEVEL FLOW. REGARDLESS IT WILL BE COOL WITH TEMPERATURES
BELOW NORMAL WITH CHANCES FOR RAIN SHOWERS OVER MUCH OF THE AREA AND
LIGHT SNOW ACCUMULATION POSSIBLE IN THE MOUNTAINS WITH THE MAIN
CHANCES FOR SNOW ACCUMULATIONS IN THE SNOWY AND SIERRA MADRE RANGES.
HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S WITH SOME 60S INTO
THE LOWER ELEVATIONS INTO THE PLAINS. HIGH TEMPERATURES IN THE
MOUNTAINS WILL BE IN THE 30S AND 40S.

THE 00Z ECMWF AND GFS SHOWING BIG DIFFERENCES IN THE PLACEMENT OF
THE UPPER TROUGH COME FRIDAY AND SATURDAY. THE ECMWF IS ACTUALLY
MORE PROGRESSIVE WITH WARMER AIR MAKING A PUSH ACROSS THE
ROCKIES...WHILE THE GFS DIGS THE UPPER TROUGH SOUTH ACROSS THE GREAT
PLAINS AND IS A GOOD DAY SLOWER BRINGING IN THE WARMER AIR.
TYPICALLY THE EASTWARD PROGRESSION OF AMPLIFIED PATTERNS IS SLOWER
THAN WHAT THE GFS INDICATED...SO KIND OF SURPRISED THE ECMWF IS SO
MUCH FASTER THAN THE GFS. THAT SAID THE ECMWF HAS BEEN PREFORMING
BETTER AT DAYS 5 THROUGH 7 SO HEDGED THE FORECAST TOWARDS THE ECMWF
FOR NOW.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1200 PM MDT SUN SEP 28 2014

CHALLENGES ARE MANY FOR THIS TAF FORECAST...INITIALLY TRYING TO
TIME A LINE OF CONVECTION LIFTING NORTH AND EAST ACROSS SE WYOMING
AND THE WRN NEBRASKA PANHANDLE...THEN TRYING TO TIME ITS DEPARTURE
AND RESIDUAL LOW CLOUD/FOG POTENTIAL LATE TONIGHT AND EARLY
MONDAY. BAND OF PRECIP IS JUST NOW BEGINNING TO LIFT NORTH ACROSS
CARBON COUNTY...WITH NO IMPACT AT KRWL JUST YET. THIS WILL CHANGE
THRU 20Z HOWEVER...AS DETERIORATING CONDITIONS ARE EXPECTED THERE.
THIS PRECIP BAND WILL THEN ACCELERATE EAST IMPACTING KLAR AFTER
21Z AND KCYS MOSTLY AFTER 00Z. AREAS EAST INTO THE PANHANDLE WILL
HAVE TO WAIT UNTIL THIS EVENING TO BE IMPACTED BY THIS AREA OF
CONVECTION. THIS AREA OF SHOWERS WILL SPREAD EAST THROUGH MONDAY
MORNING...GRADUALLY BRINGING AN END TO PRECIPITATION CHANCES FROM
WEST TO EAST. HAVE GENERALLY BOTTOMED CONDITIONS OUT IN MOST
PLACES AT MVFR/IFR. MOUNTAINS WILL BE OBSCURED AS WELL THRU MUCH
OF THE PERIOD IMPACTING ROUTES ACROSS SE WYOMING.

&&

.FIRE WEATHER...
ISSUED AT 229 AM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS THROUGH THE MIDDLE OF NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL RESULT IN HUMIDITY
VALUES TRENDING HIGHER OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY AND
MONDAY ACROSS MOST OF THE AREA. WINDY CONDITIONS WILL DEVELOP ON
TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE 35 PERCENT.

&&

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

$$

UPDATE...HAMMER
SHORT TERM...TJT
LONG TERM...SML
AVIATION...HAHN
FIRE WEATHER...TJT








000
FXUS65 KCYS 281608
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1008 AM MDT SUN SEP 28 2014

.UPDATE...
ISSUED AT 950 AM MDT SUN SEP 28 2014

AN IMPRESSIVE UPPER-LEVEL LOW CONTINUES TO SPIN ALONG THE CA/NV
BORDER THIS AM. ABUNDANT MOISTURE IS STREAMING NORTHWARD AHEAD OF
THIS FEATURE WITH THE 12Z GJT SKEW-T SHOWING PWATS UPWARDS OF 1.25
INCH. THIS AIR MASS WILL GRADUALLY SHIFT NORTHEAST TODAY AS UPPER
DIFFLUENCE INCREASES OVER THE CWA...WITH PCPN EXPECTED TO INCREASE
IN COVERAGE FROM WEST TO EAST. ADDED HEAVY RAIN TO THE GRIDS THIS
AFTN WITH DEEP MOISTURE IN PLACE. SPC HAS A SEE TEXT FOR PTNL ISO
SEVERE TSTMS LATER TODAY. THIS WOULD MOST LIKELY BE A LATER SHOW
AS WE WAIT FOR BETTER DYNAMIC SUPPORT FARTHER E. THE AREA TO WATCH
WILL BE THE DIFFERENTIAL HEATING BOUNDARY ALONG A LINE FROM CYS TO
AIA. IF MARGINAL INSTABILITY CAN BE REALIZED...LLVL AND DEEP LAYER
SHEAR PROFILES ARE IMPRESSIVE AND WOULD SUPPORT ROTATING UPDRAFTS
ACROSS FAR SOUTHEAST WY. TEMPERATURES ARE THE OTHER CHALLENGE FOR
THIS AFTN. DECREASED HIGHS A COUPLE OF DEGREES WHERE LLVL USPLOPE
IS PROVIDING FUEL FOR DENSE STRATUS.

&&

.SHORT TERM...(TODAY AND TUESDAY)
ISSUED AT 329 AM MDT SUN SEP 28 2014

FORECAST OVER THE NEXT 48 TO 60 HOURS APPEARS ON TRACK AS A
STRONG UPPER LEVEL LOW WILL GRADUALLY MOVE ACROSS THE FORECAST
AREA THROUGH TUESDAY. AS EXPECTED...THE POSITION OF THE LOW
REMAINS OVER THE WESTERN GREAT BASIN REGION EARLY THIS MORNING AS
IT HAS STALLED OVER WESTERN NEVADA. MODELS STILL SHOW THIS LOW
MOVING VERY LITTLE TODAY...AND ACTUALLY RETROGRADING SLIGHTLY INTO
THIS EVENING BEFORE THE DOMINANT LOW PRESSURE CENTER ALOFT FINALLY
EJECTS EASTWARD SOMETIME LATE TONIGHT. RAIN SHOWERS OVER CARBON
COUNTY YESTERDAY HAVE SINCE DISSIPATED WITH ONLY PARTLY CLOUDY
SKIES WEST OF THE LARAMIE RANGE. HOWEVER...SHOWER ACTIVITY IS
STARTING TO REDEVELOP AND PUSH NORTHWARD OUT OF WESTERN COLORADO.
THIS ACTIVITY IS IN ADVANCE OF A 110 KNOT JET MAX IN ASSOCIATION
WITH AN UPPER LEVEL DISTURBANCE. MATTER OF FACT...TSTORMS ARE
STILL ON GOING ACROSS ARIZONA AS THIS DISTURBANCE BEGINS TO ROUND
THE BASE OF THE UPPER LEVEL LOW CENTER. SHOWERS AND ISOLATED
THUNDER WILL GRADUALLY INCREASE IN COVERAGE WEST OF THE LARAMIE
RANGE THIS MORNING...AND THEN EVENTUALLY PUSH INTO THE LARAMIE
RANGE AND ADJACENT HIGH PLAINS LATER TODAY. SHOWERS AND TSTORMS
WILL HOLD OFF UNTIL LATE THIS EVENING FOR WESTERN NEBRASKA...DUE
TO DRY AIR ALOFT AND SOME SUBSIDENCE ON THE WESTERN EDGE OF THE
UPPER LEVEL RIDGE ACROSS THE PLAINS. KEPT POP BETWEEN 60 TO 80
PERCENT ACROSS MOST OF SOUTHEAST WYOMING AND THE NORTHERN NEBRASKA
PANHANDLE THIS EVENING...WITH PROBABILITIES OVER 90 PERCENT ACROSS
THE LARAMIE RANGE. SOME SHOWERS/TSTORMS MAY CONTAIN VERY HEAVY
RAINFALL...GUSTY WINDS...AND SMALL HAIL. HIGHS TODAY WILL
GENERALLY BE 10 DEGREES COOLER COMPARED TO SATURDAY WITH READINGS
RANGING FROM THE MID TO UPPER 60S WEST OF THE LARAMIE RANGE...AND
70S TO NEAR 80 EAST OF THE LARAMIE RANGE. RAINFALL WILL GRADUALLY
DIMINISH FROM SOUTH TO NORTH LATE TONIGHT.

FOR MONDAY...THE MAIN SYSTEM WILL MOVE ACROSS THE CENTRAL ROCKY
MOUNTAINS AND IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT AND
POSSIBLY INTO TUESDAY. WILL HAVE TO CLOSELY MONITOR THIS SYSTEM
FOR THE POTENTIAL OF FLASH FLOODING AND STRONG
THUNDERSTORMS...SINCE MODELS INDICATE THE UPPER LEVEL LOW BECOMING
A NEGATIVELY TILTED OPEN WAVE AS IT MOVES EASTWARD...AND THEN SHOW
THE LOW CLOSING OFF AGAIN SOMEWHERE IN THE VICINITY OF EAST
CENTRAL WYOMING TOWARDS THE BLACK HILLS OF SOUTH DAKOTA. MODELS
SHOW A STRONG JET MAX ALOFT BECOMING TWO INDIVIDUAL JET STREAKS
OVER THE HIGH PLAINS FORMING A FAVORABLE DIFLUENT COUPLET IN
ADDITION TO RAPID LEE-SIDE CYCLOGENESIS. THERE IS THE POTENTIAL
FOR A WIDESPREAD MODERATE TO HEAVY RAINFALL EVENT ALONG WITH RAIN
CHANGING TO SNOW IN THE MOUNTAINS ABOVE 9000 FEET. AFTER A BRIEF
LULL MONDAY MORNING WITH MAINLY DRIZZLE...LOW STRATUS AND PATCHY
FOG...SHOWERS AND TSTORMS WILL QUICKLY DEVELOP AND INCREASE IN
COVERAGE DURING THE AFTERNOON. INCREASED POP BETWEEN 70 TO 90
PERCENT ACROSS MOST OF THE HIGH PLAINS ALONG AND EAST OF THE
LARAMIE RANGE. TEMPERATURES WILL BE CLOSER TO NORMAL ON MONDAY AND
GENERALLY IN THE 60S ACROSS SOUTHEAST WYOMING AND LOW TO MID 70S
ACROSS WESTERN NEBRASKA.

VERY WINDY CONDITIONS MAY BE A CONCERN FOR LATE MONDAY NIGHT AND
TUESDAY AS THE GFS INDICATES WINDS AT 700MB OVER 55 KNOTS...MAINLY
DUE TO WINDS BECOMING WESTERLY AND RAPID CYCLOGENESIS OVER THE
HIGH PLAINS AS THE SURFACE LOW FORMS OVER NE COLORADO AND MOVES
DUE NORTH ACROSS THE BLACK HILLS. A BIT TOO EARLY TO SEE HIGH WIND
CRITERIA...ALONG MODELS HINT TOWARDS DECENT LLVL SUBSIDENCE BY
EARLY TUESDAY MORNING. WILL LIKELY NEED WIND ADVISORIES FOR
PORTIONS OF WESTERN NEBRASKA ON TUESDAY. GUSTS UP TO 55 MPH ARE
POSSIBLE ACROSS THE WIND PRONE AREAS OF SOUTHEAST WYOMING...WITH
GUSTS UP TO 45 MPH ELSEWHERE. TUESDAY WILL BE SOMEWHAT DRIER DUE
TO DOWNSLOPE WINDS...BUT RAIN SHOWERS CAN NOT BE RULED
OUT...ESPECIALLY NORTH OF I80.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MDT SUN SEP 27 2014

EXTENDED MODELS IN RELATIVELY GOOD AGREEMENT THROUGH THURSDAY WITH A
MEAN UPPER LEVEL TROUGH OVER THE WESTERN AND CENTRAL CONUS. THE
DEVIL IS IN THE DETAILS WITH CHANCES FOR PRECIPITATION MAINLY
DEPENDING ON TIMING AND PLACEMENT OF SHORTWAVE ENERGY EMBEDDED IN
THE UPPER LEVEL FLOW. REGARDLESS IT WILL BE COOL WITH TEMPERATURES
BELOW NORMAL WITH CHANCES FOR RAIN SHOWERS OVER MUCH OF THE AREA AND
LIGHT SNOW ACCUMULATION POSSIBLE IN THE MOUNTAINS WITH THE MAIN
CHANCES FOR SNOW ACCUMULATIONS IN THE SNOWY AND SIERRA MADRE RANGES.
HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S WITH SOME 60S INTO
THE LOWER ELEVATIONS INTO THE PLAINS. HIGH TEMPERATURES IN THE
MOUNTAINS WILL BE IN THE 30S AND 40S.

THE 00Z ECMWF AND GFS SHOWING BIG DIFFERENCES IN THE PLACEMENT OF
THE UPPER TROUGH COME FRIDAY AND SATURDAY. THE ECMWF IS ACTUALLY
MORE PROGRESSIVE WITH WARMER AIR MAKING A PUSH ACROSS THE
ROCKIES...WHILE THE GFS DIGS THE UPPER TROUGH SOUTH ACROSS THE GREAT
PLAINS AND IS A GOOD DAY SLOWER BRINGING IN THE WARMER AIR.
TYPICALLY THE EASTWARD PROGRESSION OF AMPLIFIED PATTERNS IS SLOWER
THAN WHAT THE GFS INDICATED...SO KIND OF SURPRISED THE ECMWF IS SO
MUCH FASTER THAN THE GFS. THAT SAID THE ECMWF HAS BEEN PREFORMING
BETTER AT DAYS 5 THROUGH 7 SO HEDGED THE FORECAST TOWARDS THE ECMWF
FOR NOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 330 AM MDT SUN SEP 28 2014

UPPER LEVEL LOW WILL NUDGE ITS WAY INTO SOUTHEAST WYOMING TODAY.
THIS WILL ALLOW FOR THE DEVELOPMENT OF AFTERNOON SHOWERS AND
THUNDERSTORMS...WHICH MAY REACH INTO THE NEBRASKA PANHANDLE LATER
TONIGHT. MAINLY LOOKING AT VFR ACROSS THE FORECAST AREA THROUGH
EARLY THIS AFTERNOON...BUT SOME MVFR CIGS WILL BE POSSIBLE NEAR THE
LARAMIE RANGE. ALREADY LOOKING AT 2000-3000 FT AGL CIGS ALONG THE
NORTHERN LARAMIE RANGE. WIDESPREAD IFR TO MVFR FOR SOUTHEAST WYOMING
TONIGHT WITH SHOWERS BECOMING WIDESPREAD MONDAY AFTERNOON WITH
ISOLATED THUNDERSTORMS.


&&

.FIRE WEATHER...
ISSUED AT 229 AM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS THROUGH THE MIDDLE OF NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL RESULT IN HUMIDITY
VALUES TRENDING HIGHER OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY AND
MONDAY ACROSS MOST OF THE AREA. WINDY CONDITIONS WILL DEVELOP ON
TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE 35 PERCENT.

&&

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

$$

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








000
FXUS65 KCYS 281608
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1008 AM MDT SUN SEP 28 2014

.UPDATE...
ISSUED AT 950 AM MDT SUN SEP 28 2014

AN IMPRESSIVE UPPER-LEVEL LOW CONTINUES TO SPIN ALONG THE CA/NV
BORDER THIS AM. ABUNDANT MOISTURE IS STREAMING NORTHWARD AHEAD OF
THIS FEATURE WITH THE 12Z GJT SKEW-T SHOWING PWATS UPWARDS OF 1.25
INCH. THIS AIR MASS WILL GRADUALLY SHIFT NORTHEAST TODAY AS UPPER
DIFFLUENCE INCREASES OVER THE CWA...WITH PCPN EXPECTED TO INCREASE
IN COVERAGE FROM WEST TO EAST. ADDED HEAVY RAIN TO THE GRIDS THIS
AFTN WITH DEEP MOISTURE IN PLACE. SPC HAS A SEE TEXT FOR PTNL ISO
SEVERE TSTMS LATER TODAY. THIS WOULD MOST LIKELY BE A LATER SHOW
AS WE WAIT FOR BETTER DYNAMIC SUPPORT FARTHER E. THE AREA TO WATCH
WILL BE THE DIFFERENTIAL HEATING BOUNDARY ALONG A LINE FROM CYS TO
AIA. IF MARGINAL INSTABILITY CAN BE REALIZED...LLVL AND DEEP LAYER
SHEAR PROFILES ARE IMPRESSIVE AND WOULD SUPPORT ROTATING UPDRAFTS
ACROSS FAR SOUTHEAST WY. TEMPERATURES ARE THE OTHER CHALLENGE FOR
THIS AFTN. DECREASED HIGHS A COUPLE OF DEGREES WHERE LLVL USPLOPE
IS PROVIDING FUEL FOR DENSE STRATUS.

&&

.SHORT TERM...(TODAY AND TUESDAY)
ISSUED AT 329 AM MDT SUN SEP 28 2014

FORECAST OVER THE NEXT 48 TO 60 HOURS APPEARS ON TRACK AS A
STRONG UPPER LEVEL LOW WILL GRADUALLY MOVE ACROSS THE FORECAST
AREA THROUGH TUESDAY. AS EXPECTED...THE POSITION OF THE LOW
REMAINS OVER THE WESTERN GREAT BASIN REGION EARLY THIS MORNING AS
IT HAS STALLED OVER WESTERN NEVADA. MODELS STILL SHOW THIS LOW
MOVING VERY LITTLE TODAY...AND ACTUALLY RETROGRADING SLIGHTLY INTO
THIS EVENING BEFORE THE DOMINANT LOW PRESSURE CENTER ALOFT FINALLY
EJECTS EASTWARD SOMETIME LATE TONIGHT. RAIN SHOWERS OVER CARBON
COUNTY YESTERDAY HAVE SINCE DISSIPATED WITH ONLY PARTLY CLOUDY
SKIES WEST OF THE LARAMIE RANGE. HOWEVER...SHOWER ACTIVITY IS
STARTING TO REDEVELOP AND PUSH NORTHWARD OUT OF WESTERN COLORADO.
THIS ACTIVITY IS IN ADVANCE OF A 110 KNOT JET MAX IN ASSOCIATION
WITH AN UPPER LEVEL DISTURBANCE. MATTER OF FACT...TSTORMS ARE
STILL ON GOING ACROSS ARIZONA AS THIS DISTURBANCE BEGINS TO ROUND
THE BASE OF THE UPPER LEVEL LOW CENTER. SHOWERS AND ISOLATED
THUNDER WILL GRADUALLY INCREASE IN COVERAGE WEST OF THE LARAMIE
RANGE THIS MORNING...AND THEN EVENTUALLY PUSH INTO THE LARAMIE
RANGE AND ADJACENT HIGH PLAINS LATER TODAY. SHOWERS AND TSTORMS
WILL HOLD OFF UNTIL LATE THIS EVENING FOR WESTERN NEBRASKA...DUE
TO DRY AIR ALOFT AND SOME SUBSIDENCE ON THE WESTERN EDGE OF THE
UPPER LEVEL RIDGE ACROSS THE PLAINS. KEPT POP BETWEEN 60 TO 80
PERCENT ACROSS MOST OF SOUTHEAST WYOMING AND THE NORTHERN NEBRASKA
PANHANDLE THIS EVENING...WITH PROBABILITIES OVER 90 PERCENT ACROSS
THE LARAMIE RANGE. SOME SHOWERS/TSTORMS MAY CONTAIN VERY HEAVY
RAINFALL...GUSTY WINDS...AND SMALL HAIL. HIGHS TODAY WILL
GENERALLY BE 10 DEGREES COOLER COMPARED TO SATURDAY WITH READINGS
RANGING FROM THE MID TO UPPER 60S WEST OF THE LARAMIE RANGE...AND
70S TO NEAR 80 EAST OF THE LARAMIE RANGE. RAINFALL WILL GRADUALLY
DIMINISH FROM SOUTH TO NORTH LATE TONIGHT.

FOR MONDAY...THE MAIN SYSTEM WILL MOVE ACROSS THE CENTRAL ROCKY
MOUNTAINS AND IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT AND
POSSIBLY INTO TUESDAY. WILL HAVE TO CLOSELY MONITOR THIS SYSTEM
FOR THE POTENTIAL OF FLASH FLOODING AND STRONG
THUNDERSTORMS...SINCE MODELS INDICATE THE UPPER LEVEL LOW BECOMING
A NEGATIVELY TILTED OPEN WAVE AS IT MOVES EASTWARD...AND THEN SHOW
THE LOW CLOSING OFF AGAIN SOMEWHERE IN THE VICINITY OF EAST
CENTRAL WYOMING TOWARDS THE BLACK HILLS OF SOUTH DAKOTA. MODELS
SHOW A STRONG JET MAX ALOFT BECOMING TWO INDIVIDUAL JET STREAKS
OVER THE HIGH PLAINS FORMING A FAVORABLE DIFLUENT COUPLET IN
ADDITION TO RAPID LEE-SIDE CYCLOGENESIS. THERE IS THE POTENTIAL
FOR A WIDESPREAD MODERATE TO HEAVY RAINFALL EVENT ALONG WITH RAIN
CHANGING TO SNOW IN THE MOUNTAINS ABOVE 9000 FEET. AFTER A BRIEF
LULL MONDAY MORNING WITH MAINLY DRIZZLE...LOW STRATUS AND PATCHY
FOG...SHOWERS AND TSTORMS WILL QUICKLY DEVELOP AND INCREASE IN
COVERAGE DURING THE AFTERNOON. INCREASED POP BETWEEN 70 TO 90
PERCENT ACROSS MOST OF THE HIGH PLAINS ALONG AND EAST OF THE
LARAMIE RANGE. TEMPERATURES WILL BE CLOSER TO NORMAL ON MONDAY AND
GENERALLY IN THE 60S ACROSS SOUTHEAST WYOMING AND LOW TO MID 70S
ACROSS WESTERN NEBRASKA.

VERY WINDY CONDITIONS MAY BE A CONCERN FOR LATE MONDAY NIGHT AND
TUESDAY AS THE GFS INDICATES WINDS AT 700MB OVER 55 KNOTS...MAINLY
DUE TO WINDS BECOMING WESTERLY AND RAPID CYCLOGENESIS OVER THE
HIGH PLAINS AS THE SURFACE LOW FORMS OVER NE COLORADO AND MOVES
DUE NORTH ACROSS THE BLACK HILLS. A BIT TOO EARLY TO SEE HIGH WIND
CRITERIA...ALONG MODELS HINT TOWARDS DECENT LLVL SUBSIDENCE BY
EARLY TUESDAY MORNING. WILL LIKELY NEED WIND ADVISORIES FOR
PORTIONS OF WESTERN NEBRASKA ON TUESDAY. GUSTS UP TO 55 MPH ARE
POSSIBLE ACROSS THE WIND PRONE AREAS OF SOUTHEAST WYOMING...WITH
GUSTS UP TO 45 MPH ELSEWHERE. TUESDAY WILL BE SOMEWHAT DRIER DUE
TO DOWNSLOPE WINDS...BUT RAIN SHOWERS CAN NOT BE RULED
OUT...ESPECIALLY NORTH OF I80.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MDT SUN SEP 27 2014

EXTENDED MODELS IN RELATIVELY GOOD AGREEMENT THROUGH THURSDAY WITH A
MEAN UPPER LEVEL TROUGH OVER THE WESTERN AND CENTRAL CONUS. THE
DEVIL IS IN THE DETAILS WITH CHANCES FOR PRECIPITATION MAINLY
DEPENDING ON TIMING AND PLACEMENT OF SHORTWAVE ENERGY EMBEDDED IN
THE UPPER LEVEL FLOW. REGARDLESS IT WILL BE COOL WITH TEMPERATURES
BELOW NORMAL WITH CHANCES FOR RAIN SHOWERS OVER MUCH OF THE AREA AND
LIGHT SNOW ACCUMULATION POSSIBLE IN THE MOUNTAINS WITH THE MAIN
CHANCES FOR SNOW ACCUMULATIONS IN THE SNOWY AND SIERRA MADRE RANGES.
HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S WITH SOME 60S INTO
THE LOWER ELEVATIONS INTO THE PLAINS. HIGH TEMPERATURES IN THE
MOUNTAINS WILL BE IN THE 30S AND 40S.

THE 00Z ECMWF AND GFS SHOWING BIG DIFFERENCES IN THE PLACEMENT OF
THE UPPER TROUGH COME FRIDAY AND SATURDAY. THE ECMWF IS ACTUALLY
MORE PROGRESSIVE WITH WARMER AIR MAKING A PUSH ACROSS THE
ROCKIES...WHILE THE GFS DIGS THE UPPER TROUGH SOUTH ACROSS THE GREAT
PLAINS AND IS A GOOD DAY SLOWER BRINGING IN THE WARMER AIR.
TYPICALLY THE EASTWARD PROGRESSION OF AMPLIFIED PATTERNS IS SLOWER
THAN WHAT THE GFS INDICATED...SO KIND OF SURPRISED THE ECMWF IS SO
MUCH FASTER THAN THE GFS. THAT SAID THE ECMWF HAS BEEN PREFORMING
BETTER AT DAYS 5 THROUGH 7 SO HEDGED THE FORECAST TOWARDS THE ECMWF
FOR NOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 330 AM MDT SUN SEP 28 2014

UPPER LEVEL LOW WILL NUDGE ITS WAY INTO SOUTHEAST WYOMING TODAY.
THIS WILL ALLOW FOR THE DEVELOPMENT OF AFTERNOON SHOWERS AND
THUNDERSTORMS...WHICH MAY REACH INTO THE NEBRASKA PANHANDLE LATER
TONIGHT. MAINLY LOOKING AT VFR ACROSS THE FORECAST AREA THROUGH
EARLY THIS AFTERNOON...BUT SOME MVFR CIGS WILL BE POSSIBLE NEAR THE
LARAMIE RANGE. ALREADY LOOKING AT 2000-3000 FT AGL CIGS ALONG THE
NORTHERN LARAMIE RANGE. WIDESPREAD IFR TO MVFR FOR SOUTHEAST WYOMING
TONIGHT WITH SHOWERS BECOMING WIDESPREAD MONDAY AFTERNOON WITH
ISOLATED THUNDERSTORMS.


&&

.FIRE WEATHER...
ISSUED AT 229 AM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS THROUGH THE MIDDLE OF NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL RESULT IN HUMIDITY
VALUES TRENDING HIGHER OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY AND
MONDAY ACROSS MOST OF THE AREA. WINDY CONDITIONS WILL DEVELOP ON
TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE 35 PERCENT.

&&

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

$$

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







000
FXUS65 KCYS 280934
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
334 AM MDT SUN SEP 28 2014

.SHORT TERM...(TODAY AND TUESDAY)
ISSUED AT 329 AM MDT SUN SEP 28 2014

FORECAST OVER THE NEXT 48 TO 60 HOURS APPEARS ON TRACK AS A
STRONG UPPER LEVEL LOW WILL GRADUALLY MOVE ACROSS THE FORECAST
AREA THROUGH TUESDAY. AS EXPECTED...THE POSITION OF THE LOW
REMAINS OVER THE WESTERN GREAT BASIN REGION EARLY THIS MORNING AS
IT HAS STALLED OVER WESTERN NEVADA. MODELS STILL SHOW THIS LOW
MOVING VERY LITTLE TODAY...AND ACTUALLY RETROGRADING SLIGHTLY INTO
THIS EVENING BEFORE THE DOMINANT LOW PRESSURE CENTER ALOFT FINALLY
EJECTS EASTWARD SOMETIME LATE TONIGHT. RAIN SHOWERS OVER CARBON
COUNTY YESTERDAY HAVE SINCE DISSIPATED WITH ONLY PARTLY CLOUDY
SKIES WEST OF THE LARAMIE RANGE. HOWEVER...SHOWER ACTIVITY IS
STARTING TO REDEVELOP AND PUSH NORTHWARD OUT OF WESTERN COLORADO.
THIS ACTIVITY IS IN ADVANCE OF A 110 KNOT JET MAX IN ASSOCIATION
WITH AN UPPER LEVEL DISTURBANCE. MATTER OF FACT...TSTORMS ARE
STILL ON GOING ACROSS ARIZONA AS THIS DISTURBANCE BEGINS TO ROUND
THE BASE OF THE UPPER LEVEL LOW CENTER. SHOWERS AND ISOLATED
THUNDER WILL GRADUALLY INCREASE IN COVERAGE WEST OF THE LARAMIE
RANGE THIS MORNING...AND THEN EVENTUALLY PUSH INTO THE LARAMIE
RANGE AND ADJACENT HIGH PLAINS LATER TODAY. SHOWERS AND TSTORMS
WILL HOLD OFF UNTIL LATE THIS EVENING FOR WESTERN NEBRASKA...DUE
TO DRY AIR ALOFT AND SOME SUBSIDENCE ON THE WESTERN EDGE OF THE
UPPER LEVEL RIDGE ACROSS THE PLAINS. KEPT POP BETWEEN 60 TO 80
PERCENT ACROSS MOST OF SOUTHEAST WYOMING AND THE NORTHERN NEBRASKA
PANHANDLE THIS EVENING...WITH PROBABILITIES OVER 90 PERCENT ACROSS
THE LARAMIE RANGE. SOME SHOWERS/TSTORMS MAY CONTAIN VERY HEAVY
RAINFALL...GUSTY WINDS...AND SMALL HAIL. HIGHS TODAY WILL
GENERALLY BE 10 DEGREES COOLER COMPARED TO SATURDAY WITH READINGS
RANGING FROM THE MID TO UPPER 60S WEST OF THE LARAMIE RANGE...AND
70S TO NEAR 80 EAST OF THE LARAMIE RANGE. RAINFALL WILL GRADUALLY
DIMINISH FROM SOUTH TO NORTH LATE TONIGHT.

FOR MONDAY...THE MAIN SYSTEM WILL MOVE ACROSS THE CENTRAL ROCKY
MOUNTAINS AND IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT AND
POSSIBLY INTO TUESDAY. WILL HAVE TO CLOSELY MONITOR THIS SYSTEM
FOR THE POTENTIAL OF FLASH FLOODING AND STRONG
THUNDERSTORMS...SINCE MODELS INDICATE THE UPPER LEVEL LOW BECOMING
A NEGATIVELY TILTED OPEN WAVE AS IT MOVES EASTWARD...AND THEN SHOW
THE LOW CLOSING OFF AGAIN SOMEWHERE IN THE VICINITY OF EAST
CENTRAL WYOMING TOWARDS THE BLACK HILLS OF SOUTH DAKOTA. MODELS
SHOW A STRONG JET MAX ALOFT BECOMING TWO INDIVIDUAL JET STREAKS
OVER THE HIGH PLAINS FORMING A FAVORABLE DIFLUENT COUPLET IN
ADDITION TO RAPID LEE-SIDE CYCLOGENESIS. THERE IS THE POTENTIAL
FOR A WIDESPREAD MODERATE TO HEAVY RAINFALL EVENT ALONG WITH RAIN
CHANGING TO SNOW IN THE MOUNTAINS ABOVE 9000 FEET. AFTER A BRIEF
LULL MONDAY MORNING WITH MAINLY DRIZZLE...LOW STRATUS AND PATCHY
FOG...SHOWERS AND TSTORMS WILL QUICKLY DEVELOP AND INCREASE IN
COVERAGE DURING THE AFTERNOON. INCREASED POP BETWEEN 70 TO 90
PERCENT ACROSS MOST OF THE HIGH PLAINS ALONG AND EAST OF THE
LARAMIE RANGE. TEMPERATURES WILL BE CLOSER TO NORMAL ON MONDAY AND
GENERALLY IN THE 60S ACROSS SOUTHEAST WYOMING AND LOW TO MID 70S
ACROSS WESTERN NEBRASKA.

VERY WINDY CONDITIONS MAY BE A CONCERN FOR LATE MONDAY NIGHT AND
TUESDAY AS THE GFS INDICATES WINDS AT 700MB OVER 55 KNOTS...MAINLY
DUE TO WINDS BECOMING WESTERLY AND RAPID CYCLOGENESIS OVER THE
HIGH PLAINS AS THE SURFACE LOW FORMS OVER NE COLORADO AND MOVES
DUE NORTH ACROSS THE BLACK HILLS. A BIT TOO EARLY TO SEE HIGH WIND
CRITERIA...ALONG MODELS HINT TOWARDS DECENT LLVL SUBSIDENCE BY
EARLY TUESDAY MORNING. WILL LIKELY NEED WIND ADVISORIES FOR
PORTIONS OF WESTERN NEBRASKA ON TUESDAY. GUSTS UP TO 55 MPH ARE
POSSIBLE ACROSS THE WIND PRONE AREAS OF SOUTHEAST WYOMING...WITH
GUSTS UP TO 45 MPH ELSEWHERE. TUESDAY WILL BE SOMEWHAT DRIER DUE
TO DOWNSLOPE WINDS...BUT RAIN SHOWERS CAN NOT BE RULED
OUT...ESPECIALLY NORTH OF I80.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MDT SUN SEP 27 2014

EXTENDED MODELS IN RELATIVELY GOOD AGREEMENT THROUGH THURSDAY WITH A
MEAN UPPER LEVEL TROUGH OVER THE WESTERN AND CENTRAL CONUS. THE
DEVIL IS IN THE DETAILS WITH CHANCES FOR PRECIPITATION MAINLY
DEPENDING ON TIMING AND PLACEMENT OF SHORTWAVE ENERGY EMBEDDED IN
THE UPPER LEVEL FLOW. REGARDLESS IT WILL BE COOL WITH TEMPERATURES
BELOW NORMAL WITH CHANCES FOR RAIN SHOWERS OVER MUCH OF THE AREA AND
LIGHT SNOW ACCUMULATION POSSIBLE IN THE MOUNTAINS WITH THE MAIN
CHANCES FOR SNOW ACCUMULATIONS IN THE SNOWY AND SIERRA MADRE RANGES.
HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S WITH SOME 60S INTO
THE LOWER ELEVATIONS INTO THE PLAINS. HIGH TEMPERATURES IN THE
MOUNTAINS WILL BE IN THE 30S AND 40S.

THE 00Z ECMWF AND GFS SHOWING BIG DIFFERENCES IN THE PLACEMENT OF
THE UPPER TROUGH COME FRIDAY AND SATURDAY. THE ECMWF IS ACTUALLY
MORE PROGRESSIVE WITH WARMER AIR MAKING A PUSH ACROSS THE
ROCKIES...WHILE THE GFS DIGS THE UPPER TROUGH SOUTH ACROSS THE GREAT
PLAINS AND IS A GOOD DAY SLOWER BRINGING IN THE WARMER AIR.
TYPICALLY THE EASTWARD PROGRESSION OF AMPLIFIED PATTERNS IS SLOWER
THAN WHAT THE GFS INDICATED...SO KIND OF SURPRISED THE ECMWF IS SO
MUCH FASTER THAN THE GFS. THAT SAID THE ECMWF HAS BEEN PREFORMING
BETTER AT DAYS 5 THROUGH 7 SO HEDGED THE FORECAST TOWARDS THE ECMWF
FOR NOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 330 AM MDT SUN SEP 28 2014

UPPER LEVEL LOW WILL NUDGE ITS WAY INTO SOUTHEAST WYOMING TODAY.
THIS WILL ALLOW FOR THE DEVELOPMENT OF AFTERNOON SHOWERS AND
THUNDERSTORMS...WHICH MAY REACH INTO THE NEBRASKA PANHANDLE LATER
TONIGHT. MAINLY LOOKING AT VFR ACROSS THE FORECAST AREA THROUGH
EARLY THIS AFTERNOON...BUT SOME MVFR CIGS WILL BE POSSIBLE NEAR THE
LARAMIE RANGE. ALREADY LOOKING AT 2000-3000 FT AGL CIGS ALONG THE
NORTHERN LARAMIE RANGE. WIDESPREAD IFR TO MVFR FOR SOUTHEAST WYOMING
TONIGHT WITH SHOWERS BECOMING WIDESPREAD MONDAY AFTERNOON WITH
ISOLATED THUNDERSTORMS.

&&

.FIRE WEATHER...
ISSUED AT 229 AM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS THROUGH THE MIDDLE OF NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL RESULT IN HUMIDITY
VALUES TRENDING HIGHER OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY AND
MONDAY ACROSS MOST OF THE AREA. WINDY CONDITIONS WILL DEVELOP ON
TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE 35 PERCENT.



&&

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

$$

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








000
FXUS65 KCYS 280934
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
334 AM MDT SUN SEP 28 2014

.SHORT TERM...(TODAY AND TUESDAY)
ISSUED AT 329 AM MDT SUN SEP 28 2014

FORECAST OVER THE NEXT 48 TO 60 HOURS APPEARS ON TRACK AS A
STRONG UPPER LEVEL LOW WILL GRADUALLY MOVE ACROSS THE FORECAST
AREA THROUGH TUESDAY. AS EXPECTED...THE POSITION OF THE LOW
REMAINS OVER THE WESTERN GREAT BASIN REGION EARLY THIS MORNING AS
IT HAS STALLED OVER WESTERN NEVADA. MODELS STILL SHOW THIS LOW
MOVING VERY LITTLE TODAY...AND ACTUALLY RETROGRADING SLIGHTLY INTO
THIS EVENING BEFORE THE DOMINANT LOW PRESSURE CENTER ALOFT FINALLY
EJECTS EASTWARD SOMETIME LATE TONIGHT. RAIN SHOWERS OVER CARBON
COUNTY YESTERDAY HAVE SINCE DISSIPATED WITH ONLY PARTLY CLOUDY
SKIES WEST OF THE LARAMIE RANGE. HOWEVER...SHOWER ACTIVITY IS
STARTING TO REDEVELOP AND PUSH NORTHWARD OUT OF WESTERN COLORADO.
THIS ACTIVITY IS IN ADVANCE OF A 110 KNOT JET MAX IN ASSOCIATION
WITH AN UPPER LEVEL DISTURBANCE. MATTER OF FACT...TSTORMS ARE
STILL ON GOING ACROSS ARIZONA AS THIS DISTURBANCE BEGINS TO ROUND
THE BASE OF THE UPPER LEVEL LOW CENTER. SHOWERS AND ISOLATED
THUNDER WILL GRADUALLY INCREASE IN COVERAGE WEST OF THE LARAMIE
RANGE THIS MORNING...AND THEN EVENTUALLY PUSH INTO THE LARAMIE
RANGE AND ADJACENT HIGH PLAINS LATER TODAY. SHOWERS AND TSTORMS
WILL HOLD OFF UNTIL LATE THIS EVENING FOR WESTERN NEBRASKA...DUE
TO DRY AIR ALOFT AND SOME SUBSIDENCE ON THE WESTERN EDGE OF THE
UPPER LEVEL RIDGE ACROSS THE PLAINS. KEPT POP BETWEEN 60 TO 80
PERCENT ACROSS MOST OF SOUTHEAST WYOMING AND THE NORTHERN NEBRASKA
PANHANDLE THIS EVENING...WITH PROBABILITIES OVER 90 PERCENT ACROSS
THE LARAMIE RANGE. SOME SHOWERS/TSTORMS MAY CONTAIN VERY HEAVY
RAINFALL...GUSTY WINDS...AND SMALL HAIL. HIGHS TODAY WILL
GENERALLY BE 10 DEGREES COOLER COMPARED TO SATURDAY WITH READINGS
RANGING FROM THE MID TO UPPER 60S WEST OF THE LARAMIE RANGE...AND
70S TO NEAR 80 EAST OF THE LARAMIE RANGE. RAINFALL WILL GRADUALLY
DIMINISH FROM SOUTH TO NORTH LATE TONIGHT.

FOR MONDAY...THE MAIN SYSTEM WILL MOVE ACROSS THE CENTRAL ROCKY
MOUNTAINS AND IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT AND
POSSIBLY INTO TUESDAY. WILL HAVE TO CLOSELY MONITOR THIS SYSTEM
FOR THE POTENTIAL OF FLASH FLOODING AND STRONG
THUNDERSTORMS...SINCE MODELS INDICATE THE UPPER LEVEL LOW BECOMING
A NEGATIVELY TILTED OPEN WAVE AS IT MOVES EASTWARD...AND THEN SHOW
THE LOW CLOSING OFF AGAIN SOMEWHERE IN THE VICINITY OF EAST
CENTRAL WYOMING TOWARDS THE BLACK HILLS OF SOUTH DAKOTA. MODELS
SHOW A STRONG JET MAX ALOFT BECOMING TWO INDIVIDUAL JET STREAKS
OVER THE HIGH PLAINS FORMING A FAVORABLE DIFLUENT COUPLET IN
ADDITION TO RAPID LEE-SIDE CYCLOGENESIS. THERE IS THE POTENTIAL
FOR A WIDESPREAD MODERATE TO HEAVY RAINFALL EVENT ALONG WITH RAIN
CHANGING TO SNOW IN THE MOUNTAINS ABOVE 9000 FEET. AFTER A BRIEF
LULL MONDAY MORNING WITH MAINLY DRIZZLE...LOW STRATUS AND PATCHY
FOG...SHOWERS AND TSTORMS WILL QUICKLY DEVELOP AND INCREASE IN
COVERAGE DURING THE AFTERNOON. INCREASED POP BETWEEN 70 TO 90
PERCENT ACROSS MOST OF THE HIGH PLAINS ALONG AND EAST OF THE
LARAMIE RANGE. TEMPERATURES WILL BE CLOSER TO NORMAL ON MONDAY AND
GENERALLY IN THE 60S ACROSS SOUTHEAST WYOMING AND LOW TO MID 70S
ACROSS WESTERN NEBRASKA.

VERY WINDY CONDITIONS MAY BE A CONCERN FOR LATE MONDAY NIGHT AND
TUESDAY AS THE GFS INDICATES WINDS AT 700MB OVER 55 KNOTS...MAINLY
DUE TO WINDS BECOMING WESTERLY AND RAPID CYCLOGENESIS OVER THE
HIGH PLAINS AS THE SURFACE LOW FORMS OVER NE COLORADO AND MOVES
DUE NORTH ACROSS THE BLACK HILLS. A BIT TOO EARLY TO SEE HIGH WIND
CRITERIA...ALONG MODELS HINT TOWARDS DECENT LLVL SUBSIDENCE BY
EARLY TUESDAY MORNING. WILL LIKELY NEED WIND ADVISORIES FOR
PORTIONS OF WESTERN NEBRASKA ON TUESDAY. GUSTS UP TO 55 MPH ARE
POSSIBLE ACROSS THE WIND PRONE AREAS OF SOUTHEAST WYOMING...WITH
GUSTS UP TO 45 MPH ELSEWHERE. TUESDAY WILL BE SOMEWHAT DRIER DUE
TO DOWNSLOPE WINDS...BUT RAIN SHOWERS CAN NOT BE RULED
OUT...ESPECIALLY NORTH OF I80.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MDT SUN SEP 27 2014

EXTENDED MODELS IN RELATIVELY GOOD AGREEMENT THROUGH THURSDAY WITH A
MEAN UPPER LEVEL TROUGH OVER THE WESTERN AND CENTRAL CONUS. THE
DEVIL IS IN THE DETAILS WITH CHANCES FOR PRECIPITATION MAINLY
DEPENDING ON TIMING AND PLACEMENT OF SHORTWAVE ENERGY EMBEDDED IN
THE UPPER LEVEL FLOW. REGARDLESS IT WILL BE COOL WITH TEMPERATURES
BELOW NORMAL WITH CHANCES FOR RAIN SHOWERS OVER MUCH OF THE AREA AND
LIGHT SNOW ACCUMULATION POSSIBLE IN THE MOUNTAINS WITH THE MAIN
CHANCES FOR SNOW ACCUMULATIONS IN THE SNOWY AND SIERRA MADRE RANGES.
HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S WITH SOME 60S INTO
THE LOWER ELEVATIONS INTO THE PLAINS. HIGH TEMPERATURES IN THE
MOUNTAINS WILL BE IN THE 30S AND 40S.

THE 00Z ECMWF AND GFS SHOWING BIG DIFFERENCES IN THE PLACEMENT OF
THE UPPER TROUGH COME FRIDAY AND SATURDAY. THE ECMWF IS ACTUALLY
MORE PROGRESSIVE WITH WARMER AIR MAKING A PUSH ACROSS THE
ROCKIES...WHILE THE GFS DIGS THE UPPER TROUGH SOUTH ACROSS THE GREAT
PLAINS AND IS A GOOD DAY SLOWER BRINGING IN THE WARMER AIR.
TYPICALLY THE EASTWARD PROGRESSION OF AMPLIFIED PATTERNS IS SLOWER
THAN WHAT THE GFS INDICATED...SO KIND OF SURPRISED THE ECMWF IS SO
MUCH FASTER THAN THE GFS. THAT SAID THE ECMWF HAS BEEN PREFORMING
BETTER AT DAYS 5 THROUGH 7 SO HEDGED THE FORECAST TOWARDS THE ECMWF
FOR NOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 330 AM MDT SUN SEP 28 2014

UPPER LEVEL LOW WILL NUDGE ITS WAY INTO SOUTHEAST WYOMING TODAY.
THIS WILL ALLOW FOR THE DEVELOPMENT OF AFTERNOON SHOWERS AND
THUNDERSTORMS...WHICH MAY REACH INTO THE NEBRASKA PANHANDLE LATER
TONIGHT. MAINLY LOOKING AT VFR ACROSS THE FORECAST AREA THROUGH
EARLY THIS AFTERNOON...BUT SOME MVFR CIGS WILL BE POSSIBLE NEAR THE
LARAMIE RANGE. ALREADY LOOKING AT 2000-3000 FT AGL CIGS ALONG THE
NORTHERN LARAMIE RANGE. WIDESPREAD IFR TO MVFR FOR SOUTHEAST WYOMING
TONIGHT WITH SHOWERS BECOMING WIDESPREAD MONDAY AFTERNOON WITH
ISOLATED THUNDERSTORMS.

&&

.FIRE WEATHER...
ISSUED AT 229 AM MDT SUN SEP 28 2014

NO FIRE WEATHER CONCERNS THROUGH THE MIDDLE OF NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL RESULT IN HUMIDITY
VALUES TRENDING HIGHER OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY AND
MONDAY ACROSS MOST OF THE AREA. WINDY CONDITIONS WILL DEVELOP ON
TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE 35 PERCENT.



&&

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

$$

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









000
FXUS65 KCYS 280625
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1225 AM MDT SUN SEP 28 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 430 PM MDT SAT SEP 27 2014

SCATTERED SHOWERS AND ISOLATED TSTMS HAVE DEVELOPED THIS AFTN OVER
PORTIONS OF CARBON COUNTY. THE FAR WESTERN PORTION OF THE CWA IS
CLOSEST TO THE MOISTURE PLUME THAT IS STREAMING NORTHWARD FROM THE
SOUTHWEST. WATER VAPOR IMAGERY SHOWS THE UPPER LOW SPINNING ACROSS
CENTRAL CALIFORNIA WITH ABUNDANT MOISTURE TO THE EAST OF IT. KEPT
POPS LARGELY CONFINED TO CARBON COUNTY THROUGH THE NIGHT AS THE
MODELS DO NOT INDICATE MUCH EASTWARD PROGRESS IN THE UPPER LEVEL
SYSTEM AND ITS ASSOCIATED MOISTURE PLUME. THAT BEGINS TO CHANGE BY
SUN AS A SHORTWAVE PIVOTS NORTHWARD ACROSS SOUTHEAST WY BY MIDDAY
THROUGH THE AFTN. WIDESPREAD RAIN WILL DEVELOP MAINLY TO THE WEST
OF THE LARAMIE RANGE DURING THE MORNING AND THEN WILL SPREAD OVER
PORTIONS OF THE PLAINS OF SOUTHEAST WYOMING THROUGH THE EARLY
EVENING. PW VALUES ARE QUITE HIGH FOR LATE SEP (GENERALLY 0.75-0.9
INCHES) DUE TO THE DEEP MOIST SOUTHERLY FLOW...SO CAN NOT RULE
OUT SOME HEAVY RAIN PRODUCERS. TEMPS WILL BE COOLER ON SUN BY
AROUND 10 DEGREES WITH MORE CLOUD COVER AND PRECIPITATION.

BY MON THE UPPER LOW RAPIDLY LIFTS TO THE NORTHEAST WITH
INCREASING UPPER LEVEL DIFFLUENCE DURING THE AFTN...ESPECIALLY
OVER THE PLAINS. THE GFS SHOWS WIDESPREAD QPF OF OVER 0.5 INCHES
TO THE EAST OF THE LARAMIE RANGE FROM 18Z SUN THRU 06Z MON. THESE
LARGE AMOUNTS MAKE SENSE WITH THE UPPER JET JUST TO THE SOUTH OF
THE AREA AND GREAT VERTICAL ASCENT. CANNOT RULE OUT A FEW STRONGER
STORMS OVER THE PANHANDLE ON MON AFTN...ALTHOUGH THE POTENTIAL
WILL BE LIMITED BY THE ABUNDANT CLOUD COVER AND MARGINAL
INSTABILITY. FRONTAL PASSAGE OCCURS LATE IN THE DAY ON MON WITH
700MB TEMPS FALLING TO ABOUT 2C. LIGHT SNOW WILL BE POSSIBLE IN
THE HIGHER ELEVATIONS OF THE SIERRA MADRE AND SNOWY RANGES FROM
THE AFTN THROUGH THE EVENING...ALTHOUGH NOT EXPECTING MUCH MORE
THAN AN INCH DUE TO THE INCREASING SUBSIDENCE BY THAT TIME. THE
FOCUS FROM MON NIGHT THRU TUES MORNING WILL SHIFT TO THE
INCREASING WINDS. THE MODELS INDICATE CYCLOGENESIS OCCURRING BY
LATE MON NIGHT OVER WESTERN SOUTH DAKOTA. 700MB WINDS OFF THE GFS
ARE 50-60 KTS OVER THE PLAINS BY SUNRISE ON TUES SO COULD BE
LOOKING AT LEAST WIND ADVISORY POTENTIAL IN THE PANHANDLE. THE
WIND PRONE AREAS OF SOUTHEAST WY COULD ALSO SEE THE FIRST HIGH
WIND EVENT OF THE SEASON.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 430 PM MDT SAT SEP 27 2014

A COOL PERIOD SHAPING UP FOR TUE-FIR AS A LONGWAVE TROUGH CONSISTING
OF SEVERAL SHORTWAVES SLOWLY SWINGS THRU. ALTHOUGH SMALL CHANCES FOR
PRECIP WILL EXIST PERIODICALLY TUE-THU...THE BEST CHANCES WILL BE NR
THE PINE RIDGE WITH THE FIRST DEPARTING SHORTWAVE ON TUESDAY AND
AGAIN WITH THE 2ND SHORTWAVE THAT PUSHES THRU CWA-WIDE ON WEDNESDAY.
WILL NEED TO KEEP ON EYE ON STRONG WIND POTENTIAL TUESDAY MORNING AS
WELL AS H7 PROGS CLIMB TO NR 50 KNOTS. ITS NOT EXACTLY A
CLIMATOLOGICALLY FAVORABLE FOR STRONG WINDS...BUT NOT OUT OF THE
REALM OF POSSIBILITY EITHER. EACH SHORTWAVE WILL PROVIDE A
REINFORCING SHOT OF COOL AIR...COOLING HIGH TEMPERATURES FROM THE
LOW 60S TUESDAY INTO THE MID/UPPER 50S BY FRIDAY. SNOW-LEVELS WILL
HOVER 9-10 KFT TUESDAY AND WEDNESDAY...DIPPING TO AROUND 8 KFT
THURSDAY MORNING...WHICH SHOULD BE THE LOWEST OF THE PERIOD.
ALTHOUGH SIGNIFICANT SNOW ACCUMULATIONS ARE NOT EXPECTED...
ELEVATIONS ABOVE 8 KFT COULD SEE A SKIFF UP TO SEVERAL INCHES AT THE
HIGHER PEAKS...ESPECIALLY ON WEDNESDAY. ONE FINAL SHORTWAVE DROPS
SOUTHEAST WITHIN THE NW FLOW ON THURSDAY...MAINLY IMPACTING AREAS
FROM THE NRN LARAMIE RANGE EAST ALONG THE PINE RIDGE. FRIDAY LOOKS
DRY AT THIS POINT AND LIKELY STILL COOL AS THE PATTERN TRANSITIONS
FROM CYCLONIC TOWARDS ANTICYCLONIC AHEAD OF WARMING ANTICIPATED NEXT
WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM MDT SUN SEP 28 2014

MOSTLY VFR ACROSS THE FORECAST AREA THROUGH SUNDAY MORNING WITH
SOME PATCHY IFR FOG POSSIBLE ALONG THE SOUTHERN LARAMIE RANGE
TOWARD SUNRISE. UPPER LEVEL LOW WILL PRODUCE SHOWERS AND
THUNDERSTORMS MAINLY OVER SOUTHEAST WYOMING SUNDAY AFTERNOON.
SHOWERS WILL CONTINUE OVER SOUTHEAST WYOMING SUNDAY NIGHT BUT
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS WILL OCCUR MONDAY
AFTERNOON AS AN UPPER LEVEL LOW MOVES OVER THE AREA.

&&

.FIRE WEATHER...
ISSUED AT 430 PM MDT SAT SEP 27 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL CAUSE AFTERNOON
HUMIDITY VALUES TO RISE OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY ACROSS
SOUTHEAST WYOMING AND THEN OVER THE PLAINS OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE ON MONDAY. WINDY CONDITIONS
WILL DEVELOP ON TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES
WILL REMAIN ABOVE 35 PERCENT.

&&

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

$$

SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...SML
FIRE WEATHER...FINCH








000
FXUS65 KCYS 280625
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1225 AM MDT SUN SEP 28 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 430 PM MDT SAT SEP 27 2014

SCATTERED SHOWERS AND ISOLATED TSTMS HAVE DEVELOPED THIS AFTN OVER
PORTIONS OF CARBON COUNTY. THE FAR WESTERN PORTION OF THE CWA IS
CLOSEST TO THE MOISTURE PLUME THAT IS STREAMING NORTHWARD FROM THE
SOUTHWEST. WATER VAPOR IMAGERY SHOWS THE UPPER LOW SPINNING ACROSS
CENTRAL CALIFORNIA WITH ABUNDANT MOISTURE TO THE EAST OF IT. KEPT
POPS LARGELY CONFINED TO CARBON COUNTY THROUGH THE NIGHT AS THE
MODELS DO NOT INDICATE MUCH EASTWARD PROGRESS IN THE UPPER LEVEL
SYSTEM AND ITS ASSOCIATED MOISTURE PLUME. THAT BEGINS TO CHANGE BY
SUN AS A SHORTWAVE PIVOTS NORTHWARD ACROSS SOUTHEAST WY BY MIDDAY
THROUGH THE AFTN. WIDESPREAD RAIN WILL DEVELOP MAINLY TO THE WEST
OF THE LARAMIE RANGE DURING THE MORNING AND THEN WILL SPREAD OVER
PORTIONS OF THE PLAINS OF SOUTHEAST WYOMING THROUGH THE EARLY
EVENING. PW VALUES ARE QUITE HIGH FOR LATE SEP (GENERALLY 0.75-0.9
INCHES) DUE TO THE DEEP MOIST SOUTHERLY FLOW...SO CAN NOT RULE
OUT SOME HEAVY RAIN PRODUCERS. TEMPS WILL BE COOLER ON SUN BY
AROUND 10 DEGREES WITH MORE CLOUD COVER AND PRECIPITATION.

BY MON THE UPPER LOW RAPIDLY LIFTS TO THE NORTHEAST WITH
INCREASING UPPER LEVEL DIFFLUENCE DURING THE AFTN...ESPECIALLY
OVER THE PLAINS. THE GFS SHOWS WIDESPREAD QPF OF OVER 0.5 INCHES
TO THE EAST OF THE LARAMIE RANGE FROM 18Z SUN THRU 06Z MON. THESE
LARGE AMOUNTS MAKE SENSE WITH THE UPPER JET JUST TO THE SOUTH OF
THE AREA AND GREAT VERTICAL ASCENT. CANNOT RULE OUT A FEW STRONGER
STORMS OVER THE PANHANDLE ON MON AFTN...ALTHOUGH THE POTENTIAL
WILL BE LIMITED BY THE ABUNDANT CLOUD COVER AND MARGINAL
INSTABILITY. FRONTAL PASSAGE OCCURS LATE IN THE DAY ON MON WITH
700MB TEMPS FALLING TO ABOUT 2C. LIGHT SNOW WILL BE POSSIBLE IN
THE HIGHER ELEVATIONS OF THE SIERRA MADRE AND SNOWY RANGES FROM
THE AFTN THROUGH THE EVENING...ALTHOUGH NOT EXPECTING MUCH MORE
THAN AN INCH DUE TO THE INCREASING SUBSIDENCE BY THAT TIME. THE
FOCUS FROM MON NIGHT THRU TUES MORNING WILL SHIFT TO THE
INCREASING WINDS. THE MODELS INDICATE CYCLOGENESIS OCCURRING BY
LATE MON NIGHT OVER WESTERN SOUTH DAKOTA. 700MB WINDS OFF THE GFS
ARE 50-60 KTS OVER THE PLAINS BY SUNRISE ON TUES SO COULD BE
LOOKING AT LEAST WIND ADVISORY POTENTIAL IN THE PANHANDLE. THE
WIND PRONE AREAS OF SOUTHEAST WY COULD ALSO SEE THE FIRST HIGH
WIND EVENT OF THE SEASON.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 430 PM MDT SAT SEP 27 2014

A COOL PERIOD SHAPING UP FOR TUE-FIR AS A LONGWAVE TROUGH CONSISTING
OF SEVERAL SHORTWAVES SLOWLY SWINGS THRU. ALTHOUGH SMALL CHANCES FOR
PRECIP WILL EXIST PERIODICALLY TUE-THU...THE BEST CHANCES WILL BE NR
THE PINE RIDGE WITH THE FIRST DEPARTING SHORTWAVE ON TUESDAY AND
AGAIN WITH THE 2ND SHORTWAVE THAT PUSHES THRU CWA-WIDE ON WEDNESDAY.
WILL NEED TO KEEP ON EYE ON STRONG WIND POTENTIAL TUESDAY MORNING AS
WELL AS H7 PROGS CLIMB TO NR 50 KNOTS. ITS NOT EXACTLY A
CLIMATOLOGICALLY FAVORABLE FOR STRONG WINDS...BUT NOT OUT OF THE
REALM OF POSSIBILITY EITHER. EACH SHORTWAVE WILL PROVIDE A
REINFORCING SHOT OF COOL AIR...COOLING HIGH TEMPERATURES FROM THE
LOW 60S TUESDAY INTO THE MID/UPPER 50S BY FRIDAY. SNOW-LEVELS WILL
HOVER 9-10 KFT TUESDAY AND WEDNESDAY...DIPPING TO AROUND 8 KFT
THURSDAY MORNING...WHICH SHOULD BE THE LOWEST OF THE PERIOD.
ALTHOUGH SIGNIFICANT SNOW ACCUMULATIONS ARE NOT EXPECTED...
ELEVATIONS ABOVE 8 KFT COULD SEE A SKIFF UP TO SEVERAL INCHES AT THE
HIGHER PEAKS...ESPECIALLY ON WEDNESDAY. ONE FINAL SHORTWAVE DROPS
SOUTHEAST WITHIN THE NW FLOW ON THURSDAY...MAINLY IMPACTING AREAS
FROM THE NRN LARAMIE RANGE EAST ALONG THE PINE RIDGE. FRIDAY LOOKS
DRY AT THIS POINT AND LIKELY STILL COOL AS THE PATTERN TRANSITIONS
FROM CYCLONIC TOWARDS ANTICYCLONIC AHEAD OF WARMING ANTICIPATED NEXT
WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM MDT SUN SEP 28 2014

MOSTLY VFR ACROSS THE FORECAST AREA THROUGH SUNDAY MORNING WITH
SOME PATCHY IFR FOG POSSIBLE ALONG THE SOUTHERN LARAMIE RANGE
TOWARD SUNRISE. UPPER LEVEL LOW WILL PRODUCE SHOWERS AND
THUNDERSTORMS MAINLY OVER SOUTHEAST WYOMING SUNDAY AFTERNOON.
SHOWERS WILL CONTINUE OVER SOUTHEAST WYOMING SUNDAY NIGHT BUT
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS WILL OCCUR MONDAY
AFTERNOON AS AN UPPER LEVEL LOW MOVES OVER THE AREA.

&&

.FIRE WEATHER...
ISSUED AT 430 PM MDT SAT SEP 27 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL CAUSE AFTERNOON
HUMIDITY VALUES TO RISE OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY ACROSS
SOUTHEAST WYOMING AND THEN OVER THE PLAINS OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE ON MONDAY. WINDY CONDITIONS
WILL DEVELOP ON TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES
WILL REMAIN ABOVE 35 PERCENT.

&&

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

$$

SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...SML
FIRE WEATHER...FINCH







000
FXUS65 KCYS 272348
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
548 PM MDT SAT SEP 27 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 430 PM MDT SAT SEP 27 2014

SCATTERED SHOWERS AND ISOLATED TSTMS HAVE DEVELOPED THIS AFTN OVER
PORTIONS OF CARBON COUNTY. THE FAR WESTERN PORTION OF THE CWA IS
CLOSEST TO THE MOISTURE PLUME THAT IS STREAMING NORTHWARD FROM THE
SOUTHWEST. WATER VAPOR IMAGERY SHOWS THE UPPER LOW SPINNING ACROSS
CENTRAL CALIFORNIA WITH ABUNDANT MOISTURE TO THE EAST OF IT. KEPT
POPS LARGELY CONFINED TO CARBON COUNTY THROUGH THE NIGHT AS THE
MODELS DO NOT INDICATE MUCH EASTWARD PROGRESS IN THE UPPER LEVEL
SYSTEM AND ITS ASSOCIATED MOISTURE PLUME. THAT BEGINS TO CHANGE BY
SUN AS A SHORTWAVE PIVOTS NORTHWARD ACROSS SOUTHEAST WY BY MIDDAY
THROUGH THE AFTN. WIDESPREAD RAIN WILL DEVELOP MAINLY TO THE WEST
OF THE LARAMIE RANGE DURING THE MORNING AND THEN WILL SPREAD OVER
PORTIONS OF THE PLAINS OF SOUTHEAST WYOMING THROUGH THE EARLY
EVENING. PW VALUES ARE QUITE HIGH FOR LATE SEP (GENERALLY 0.75-0.9
INCHES) DUE TO THE DEEP MOIST SOUTHERLY FLOW...SO CAN NOT RULE
OUT SOME HEAVY RAIN PRODUCERS. TEMPS WILL BE COOLER ON SUN BY
AROUND 10 DEGREES WITH MORE CLOUD COVER AND PRECIPITATION.

BY MON THE UPPER LOW RAPIDLY LIFTS TO THE NORTHEAST WITH
INCREASING UPPER LEVEL DIFFLUENCE DURING THE AFTN...ESPECIALLY
OVER THE PLAINS. THE GFS SHOWS WIDESPREAD QPF OF OVER 0.5 INCHES
TO THE EAST OF THE LARAMIE RANGE FROM 18Z SUN THRU 06Z MON. THESE
LARGE AMOUNTS MAKE SENSE WITH THE UPPER JET JUST TO THE SOUTH OF
THE AREA AND GREAT VERTICAL ASCENT. CANNOT RULE OUT A FEW STRONGER
STORMS OVER THE PANHANDLE ON MON AFTN...ALTHOUGH THE POTENTIAL
WILL BE LIMITED BY THE ABUNDANT CLOUD COVER AND MARGINAL
INSTABILITY. FRONTAL PASSAGE OCCURS LATE IN THE DAY ON MON WITH
700MB TEMPS FALLING TO ABOUT 2C. LIGHT SNOW WILL BE POSSIBLE IN
THE HIGHER ELEVATIONS OF THE SIERRA MADRE AND SNOWY RANGES FROM
THE AFTN THROUGH THE EVENING...ALTHOUGH NOT EXPECTING MUCH MORE
THAN AN INCH DUE TO THE INCREASING SUBSIDENCE BY THAT TIME. THE
FOCUS FROM MON NIGHT THRU TUES MORNING WILL SHIFT TO THE
INCREASING WINDS. THE MODELS INDICATE CYCLOGENESIS OCCURRING BY
LATE MON NIGHT OVER WESTERN SOUTH DAKOTA. 700MB WINDS OFF THE GFS
ARE 50-60 KTS OVER THE PLAINS BY SUNRISE ON TUES SO COULD BE
LOOKING AT LEAST WIND ADVISORY POTENTIAL IN THE PANHANDLE. THE
WIND PRONE AREAS OF SOUTHEAST WY COULD ALSO SEE THE FIRST HIGH
WIND EVENT OF THE SEASON.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 430 PM MDT SAT SEP 27 2014

A COOL PERIOD SHAPING UP FOR TUE-FIR AS A LONGWAVE TROUGH CONSISTING
OF SEVERAL SHORTWAVES SLOWLY SWINGS THRU. ALTHOUGH SMALL CHANCES FOR
PRECIP WILL EXIST PERIODICALLY TUE-THU...THE BEST CHANCES WILL BE NR
THE PINE RIDGE WITH THE FIRST DEPARTING SHORTWAVE ON TUESDAY AND
AGAIN WITH THE 2ND SHORTWAVE THAT PUSHES THRU CWA-WIDE ON WEDNESDAY.
WILL NEED TO KEEP ON EYE ON STRONG WIND POTENTIAL TUESDAY MORNING AS
WELL AS H7 PROGS CLIMB TO NR 50 KNOTS. ITS NOT EXACTLY A
CLIMATOLOGICALLY FAVORABLE FOR STRONG WINDS...BUT NOT OUT OF THE
REALM OF POSSIBILITY EITHER. EACH SHORTWAVE WILL PROVIDE A
REINFORCING SHOT OF COOL AIR...COOLING HIGH TEMPERATURES FROM THE
LOW 60S TUESDAY INTO THE MID/UPPER 50S BY FRIDAY. SNOW-LEVELS WILL
HOVER 9-10 KFT TUESDAY AND WEDNESDAY...DIPPING TO AROUND 8 KFT
THURSDAY MORNING...WHICH SHOULD BE THE LOWEST OF THE PERIOD.
ALTHOUGH SIGNIFICANT SNOW ACCUMULATIONS ARE NOT EXPECTED...
ELEVATIONS ABOVE 8 KFT COULD SEE A SKIFF UP TO SEVERAL INCHES AT THE
HIGHER PEAKS...ESPECIALLY ON WEDNESDAY. ONE FINAL SHORTWAVE DROPS
SOUTHEAST WITHIN THE NW FLOW ON THURSDAY...MAINLY IMPACTING AREAS
FROM THE NRN LARAMIE RANGE EAST ALONG THE PINE RIDGE. FRIDAY LOOKS
DRY AT THIS POINT AND LIKELY STILL COOL AS THE PATTERN TRANSITIONS
FROM CYCLONIC TOWARDS ANTICYCLONIC AHEAD OF WARMING ANTICIPATED NEXT
WEEKEND.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON)
ISSUED AT 548 PM MDT SAT SEP 27 2014

MAIN CONCERN IN THE NEAR TERM WILL BE CONTINUED DEVELOPMENT OF
CONVECTION OVER THE MOUNTAINS PUSHING NNW AND POSSIBLE IMPACTING
KRWL. MARGINAL MVFR CONDITIONS WILL OCCUR WITH ANY SHRA/TSRA
ACTIVITY THAT MOVES OVERHEAD THRU ABOUT 06Z...WITH MOSTLY DRY
CONDITIONS EXPECTED THRU THE MORNING HERE. ELSEWHERE...WILL SEE
CONTINUED DRY AND BREEZY CONDITIONS THIS EVENING WITH WINDS
DIMINISHING OVERNIGHT. FORECAST SOUNDINGS HINT AT THE POSSIBILITY
OF FOG AT THE NEBRASKA TERMINALS EARLY SUNDAY MORNING IN SOUTHEAST
UPSLOPE FLOW...BUT CONFIDENCE RIGHT NOW IS LOW IN FOG DEVELOPING
AS THE FLOW WILL BE RELATIVELY WEAK. LEFT MENTION OF FOG OUT OF
THE FORECAST NOW...BUT WILL RE-EVALUATE FOR 06Z TAFS. A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL DEVELOP SUNDAY MORNING
IN THE FAR WEST...AND STEADILY PUSH EAST THROUGH THE AFTERNOON AND
EVENING.

&&

.FIRE WEATHER...
ISSUED AT 430 PM MDT SAT SEP 27 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL CAUSE AFTERNOON
HUMIDITY VALUES TO RISE OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY ACROSS
SOUTHEAST WYOMING AND THEN OVER THE PLAINS OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE ON MONDAY. WINDY CONDITIONS
WILL DEVELOP ON TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES
WILL REMAIN ABOVE 35 PERCENT.

&&

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

$$

SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...RJM
FIRE WEATHER...FINCH









000
FXUS65 KCYS 272348
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
548 PM MDT SAT SEP 27 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 430 PM MDT SAT SEP 27 2014

SCATTERED SHOWERS AND ISOLATED TSTMS HAVE DEVELOPED THIS AFTN OVER
PORTIONS OF CARBON COUNTY. THE FAR WESTERN PORTION OF THE CWA IS
CLOSEST TO THE MOISTURE PLUME THAT IS STREAMING NORTHWARD FROM THE
SOUTHWEST. WATER VAPOR IMAGERY SHOWS THE UPPER LOW SPINNING ACROSS
CENTRAL CALIFORNIA WITH ABUNDANT MOISTURE TO THE EAST OF IT. KEPT
POPS LARGELY CONFINED TO CARBON COUNTY THROUGH THE NIGHT AS THE
MODELS DO NOT INDICATE MUCH EASTWARD PROGRESS IN THE UPPER LEVEL
SYSTEM AND ITS ASSOCIATED MOISTURE PLUME. THAT BEGINS TO CHANGE BY
SUN AS A SHORTWAVE PIVOTS NORTHWARD ACROSS SOUTHEAST WY BY MIDDAY
THROUGH THE AFTN. WIDESPREAD RAIN WILL DEVELOP MAINLY TO THE WEST
OF THE LARAMIE RANGE DURING THE MORNING AND THEN WILL SPREAD OVER
PORTIONS OF THE PLAINS OF SOUTHEAST WYOMING THROUGH THE EARLY
EVENING. PW VALUES ARE QUITE HIGH FOR LATE SEP (GENERALLY 0.75-0.9
INCHES) DUE TO THE DEEP MOIST SOUTHERLY FLOW...SO CAN NOT RULE
OUT SOME HEAVY RAIN PRODUCERS. TEMPS WILL BE COOLER ON SUN BY
AROUND 10 DEGREES WITH MORE CLOUD COVER AND PRECIPITATION.

BY MON THE UPPER LOW RAPIDLY LIFTS TO THE NORTHEAST WITH
INCREASING UPPER LEVEL DIFFLUENCE DURING THE AFTN...ESPECIALLY
OVER THE PLAINS. THE GFS SHOWS WIDESPREAD QPF OF OVER 0.5 INCHES
TO THE EAST OF THE LARAMIE RANGE FROM 18Z SUN THRU 06Z MON. THESE
LARGE AMOUNTS MAKE SENSE WITH THE UPPER JET JUST TO THE SOUTH OF
THE AREA AND GREAT VERTICAL ASCENT. CANNOT RULE OUT A FEW STRONGER
STORMS OVER THE PANHANDLE ON MON AFTN...ALTHOUGH THE POTENTIAL
WILL BE LIMITED BY THE ABUNDANT CLOUD COVER AND MARGINAL
INSTABILITY. FRONTAL PASSAGE OCCURS LATE IN THE DAY ON MON WITH
700MB TEMPS FALLING TO ABOUT 2C. LIGHT SNOW WILL BE POSSIBLE IN
THE HIGHER ELEVATIONS OF THE SIERRA MADRE AND SNOWY RANGES FROM
THE AFTN THROUGH THE EVENING...ALTHOUGH NOT EXPECTING MUCH MORE
THAN AN INCH DUE TO THE INCREASING SUBSIDENCE BY THAT TIME. THE
FOCUS FROM MON NIGHT THRU TUES MORNING WILL SHIFT TO THE
INCREASING WINDS. THE MODELS INDICATE CYCLOGENESIS OCCURRING BY
LATE MON NIGHT OVER WESTERN SOUTH DAKOTA. 700MB WINDS OFF THE GFS
ARE 50-60 KTS OVER THE PLAINS BY SUNRISE ON TUES SO COULD BE
LOOKING AT LEAST WIND ADVISORY POTENTIAL IN THE PANHANDLE. THE
WIND PRONE AREAS OF SOUTHEAST WY COULD ALSO SEE THE FIRST HIGH
WIND EVENT OF THE SEASON.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 430 PM MDT SAT SEP 27 2014

A COOL PERIOD SHAPING UP FOR TUE-FIR AS A LONGWAVE TROUGH CONSISTING
OF SEVERAL SHORTWAVES SLOWLY SWINGS THRU. ALTHOUGH SMALL CHANCES FOR
PRECIP WILL EXIST PERIODICALLY TUE-THU...THE BEST CHANCES WILL BE NR
THE PINE RIDGE WITH THE FIRST DEPARTING SHORTWAVE ON TUESDAY AND
AGAIN WITH THE 2ND SHORTWAVE THAT PUSHES THRU CWA-WIDE ON WEDNESDAY.
WILL NEED TO KEEP ON EYE ON STRONG WIND POTENTIAL TUESDAY MORNING AS
WELL AS H7 PROGS CLIMB TO NR 50 KNOTS. ITS NOT EXACTLY A
CLIMATOLOGICALLY FAVORABLE FOR STRONG WINDS...BUT NOT OUT OF THE
REALM OF POSSIBILITY EITHER. EACH SHORTWAVE WILL PROVIDE A
REINFORCING SHOT OF COOL AIR...COOLING HIGH TEMPERATURES FROM THE
LOW 60S TUESDAY INTO THE MID/UPPER 50S BY FRIDAY. SNOW-LEVELS WILL
HOVER 9-10 KFT TUESDAY AND WEDNESDAY...DIPPING TO AROUND 8 KFT
THURSDAY MORNING...WHICH SHOULD BE THE LOWEST OF THE PERIOD.
ALTHOUGH SIGNIFICANT SNOW ACCUMULATIONS ARE NOT EXPECTED...
ELEVATIONS ABOVE 8 KFT COULD SEE A SKIFF UP TO SEVERAL INCHES AT THE
HIGHER PEAKS...ESPECIALLY ON WEDNESDAY. ONE FINAL SHORTWAVE DROPS
SOUTHEAST WITHIN THE NW FLOW ON THURSDAY...MAINLY IMPACTING AREAS
FROM THE NRN LARAMIE RANGE EAST ALONG THE PINE RIDGE. FRIDAY LOOKS
DRY AT THIS POINT AND LIKELY STILL COOL AS THE PATTERN TRANSITIONS
FROM CYCLONIC TOWARDS ANTICYCLONIC AHEAD OF WARMING ANTICIPATED NEXT
WEEKEND.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON)
ISSUED AT 548 PM MDT SAT SEP 27 2014

MAIN CONCERN IN THE NEAR TERM WILL BE CONTINUED DEVELOPMENT OF
CONVECTION OVER THE MOUNTAINS PUSHING NNW AND POSSIBLE IMPACTING
KRWL. MARGINAL MVFR CONDITIONS WILL OCCUR WITH ANY SHRA/TSRA
ACTIVITY THAT MOVES OVERHEAD THRU ABOUT 06Z...WITH MOSTLY DRY
CONDITIONS EXPECTED THRU THE MORNING HERE. ELSEWHERE...WILL SEE
CONTINUED DRY AND BREEZY CONDITIONS THIS EVENING WITH WINDS
DIMINISHING OVERNIGHT. FORECAST SOUNDINGS HINT AT THE POSSIBILITY
OF FOG AT THE NEBRASKA TERMINALS EARLY SUNDAY MORNING IN SOUTHEAST
UPSLOPE FLOW...BUT CONFIDENCE RIGHT NOW IS LOW IN FOG DEVELOPING
AS THE FLOW WILL BE RELATIVELY WEAK. LEFT MENTION OF FOG OUT OF
THE FORECAST NOW...BUT WILL RE-EVALUATE FOR 06Z TAFS. A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL DEVELOP SUNDAY MORNING
IN THE FAR WEST...AND STEADILY PUSH EAST THROUGH THE AFTERNOON AND
EVENING.

&&

.FIRE WEATHER...
ISSUED AT 430 PM MDT SAT SEP 27 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL CAUSE AFTERNOON
HUMIDITY VALUES TO RISE OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY ACROSS
SOUTHEAST WYOMING AND THEN OVER THE PLAINS OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE ON MONDAY. WINDY CONDITIONS
WILL DEVELOP ON TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES
WILL REMAIN ABOVE 35 PERCENT.

&&

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

$$

SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...RJM
FIRE WEATHER...FINCH








000
FXUS65 KCYS 272249
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
449 PM MDT SAT SEP 27 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 430 PM MDT SAT SEP 27 2014

SCATTERED SHOWERS AND ISOLATED TSTMS HAVE DEVELOPED THIS AFTN OVER
PORTIONS OF CARBON COUNTY. THE FAR WESTERN PORTION OF THE CWA IS
CLOSEST TO THE MOISTURE PLUME THAT IS STREAMING NORTHWARD FROM THE
SOUTHWEST. WATER VAPOR IMAGERY SHOWS THE UPPER LOW SPINNING ACROSS
CENTRAL CALIFORNIA WITH ABUNDANT MOISTURE TO THE EAST OF IT. KEPT
POPS LARGELY CONFINED TO CARBON COUNTY THROUGH THE NIGHT AS THE
MODELS DO NOT INDICATE MUCH EASTWARD PROGRESS IN THE UPPER LEVEL
SYSTEM AND ITS ASSOCIATED MOISTURE PLUME. THAT BEGINS TO CHANGE BY
SUN AS A SHORTWAVE PIVOTS NORTHWARD ACROSS SOUTHEAST WY BY MIDDAY
THROUGH THE AFTN. WIDESPREAD RAIN WILL DEVELOP MAINLY TO THE WEST
OF THE LARAMIE RANGE DURING THE MORNING AND THEN WILL SPREAD OVER
PORTIONS OF THE PLAINS OF SOUTHEAST WYOMING THROUGH THE EARLY
EVENING. PW VALUES ARE QUITE HIGH FOR LATE SEP (GENERALLY 0.75-0.9
INCHES) DUE TO THE DEEP MOIST SOUTHERLY FLOW...SO CAN NOT RULE
OUT SOME HEAVY RAIN PRODUCERS. TEMPS WILL BE COOLER ON SUN BY
AROUND 10 DEGREES WITH MORE CLOUD COVER AND PRECIPITATION.

BY MON THE UPPER LOW RAPIDLY LIFTS TO THE NORTHEAST WITH
INCREASING UPPER LEVEL DIFFLUENCE DURING THE AFTN...ESPECIALLY
OVER THE PLAINS. THE GFS SHOWS WIDESPREAD QPF OF OVER 0.5 INCHES
TO THE EAST OF THE LARAMIE RANGE FROM 18Z SUN THRU 06Z MON. THESE
LARGE AMOUNTS MAKE SENSE WITH THE UPPER JET JUST TO THE SOUTH OF
THE AREA AND GREAT VERTICAL ASCENT. CANNOT RULE OUT A FEW STRONGER
STORMS OVER THE PANHANDLE ON MON AFTN...ALTHOUGH THE POTENTIAL
WILL BE LIMITED BY THE ABUNDANT CLOUD COVER AND MARGINAL
INSTABILITY. FRONTAL PASSAGE OCCURS LATE IN THE DAY ON MON WITH
7OOMB TEMPS FALLING TO ABOUT 2C. LIGHT SNOW WILL BE POSSIBLE IN
THE HIGHER ELEVATIONS OF THE SIERRA MADRE AND SNOWY RANGES FROM
THE AFTN THROUGH THE EVENING...ALTHOUGH NOT EXPECTING MUCH MORE
THAN AN INCH DUE TO THE INCREASING SUBSIDENCE BY THAT TIME. THE
FOCUS FROM MON NIGHT THRU TUES MORNING WILL SHIFT TO THE
INCREASING WINDS. THE MODELS INDICATE CYCLOGENESIS OCCURRING BY
LATE MON NIGHT OVER WESTERN SOUTH DAKOTA. 700MB WINDS OFF THE GFS
ARE 50-60 KTS OVER THE PLAINS BY SUNRISE ON TUES SO COULD BE
LOOKING AT LEAST WIND ADVISORY POTENTIAL IN THE PANHANDLE. THE
WIND PRONE AREAS OF SOUTHEAST WY COULD ALSO SEE THE FIRST HIGH
WIND EVENT OF THE SEASON.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 430 PM MDT SAT SEP 27 2014

A COOL PERIOD SHAPING UP FOR TUE-FIR AS A LONGWAVE TROUGH CONSISTING
OF SEVERAL SHORTWAVES SLOWLY SWINGS THRU. ALTHOUGH SMALL CHANCES FOR
PRECIP WILL EXIST PERIODICALLY TUE-THU...THE BEST CHANCES WILL BE NR
THE PINE RIDGE WITH THE FIRST DEPARTING SHORTWAVE ON TUESDAY AND
AGAIN WITH THE 2ND SHORTWAVE THAT PUSHES THRU CWA-WIDE ON WEDNESDAY.
WILL NEED TO KEEP ON EYE ON STRONG WIND POTENTIAL TUESDAY MORNING AS
WELL AS H7 PROGS CLIMB TO NR 50 KNOTS. ITS NOT EXACTLY A
CLIMATOLOGICALLY FAVORABLE FOR STRONG WINDS...BUT NOT OUT OF THE
REALM OF POSSIBILITY EITHER. EACH SHORTWAVE WILL PROVIDE A
REINFORCING SHOT OF COOL AIR...COOLING HIGH TEMPERATURES FROM THE
LOW 60S TUESDAY INTO THE MID/UPPER 50S BY FRIDAY. SNOW-LEVELS WILL
HOVER 9-10 KFT TUESDAY AND WEDNESDAY...DIPPING TO AROUND 8 KFT
THURSDAY MORNING...WHICH SHOULD BE THE LOWEST OF THE PERIOD.
ALTHOUGH SIGNIFICANT SNOW ACCUMULATIONS ARE NOT EXPECTED...
ELEVATIONS ABOVE 8 KFT COULD SEE A SKIFF UP TO SEVERAL INCHES AT THE
HIGHER PEAKS...ESPECIALLY ON WEDNESDAY. ONE FINAL SHORTWAVE DROPS
SOUTHEAST WITHIN THE NW FLOW ON THURSDAY...MAINLY IMPACTING AREAS
FROM THE NRN LARAMIE RANGE EAST ALONG THE PINE RIDGE. FRIDAY LOOKS
DRY AT THIS POINT AND LIKELY STILL COOL AS THE PATTERN TRANSITIONS
FROM CYCLONIC TOWARDS ANTICYCLONIC AHEAD OF WARMING ANTICIPATED NEXT
WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1215 PM MDT SAT SEP 27 2014

VFR CONDITIONS TO PREVAIL AT MOST SITES THROUGH THIS UPCOMING
PERIOD. THE EXCEPTION WILL BE AT KRWL...WHERE ISOLATED CONVECTION
WILL PUSH NORTH OFF OF THE SIERRA MADRE RANGE BETWEEN 21-04Z.
SHOULD ALSO SEE SOME LOWER MVFR CIGS PUSH INTO KRWL AFTER 12Z
SUNDAY AS WELL...AS THE LOW PRESSURE AREA APPROACHES. A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE JUST BEYOND THIS
PERIOD...SUNDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 430 PM MDT SAT SEP 27 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL CAUSE AFTERNOON
HUMIDITY VALUES TO RISE OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY ACROSS
SOUTHEAST WYOMING AND THEN OVER THE PLAINS OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE ON MONDAY. WINDY CONDITIONS
WILL DEVELOP ON TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES
WILL REMAIN ABOVE 35 PERCENT.

&&

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

$$

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





000
FXUS65 KCYS 272249
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
449 PM MDT SAT SEP 27 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 430 PM MDT SAT SEP 27 2014

SCATTERED SHOWERS AND ISOLATED TSTMS HAVE DEVELOPED THIS AFTN OVER
PORTIONS OF CARBON COUNTY. THE FAR WESTERN PORTION OF THE CWA IS
CLOSEST TO THE MOISTURE PLUME THAT IS STREAMING NORTHWARD FROM THE
SOUTHWEST. WATER VAPOR IMAGERY SHOWS THE UPPER LOW SPINNING ACROSS
CENTRAL CALIFORNIA WITH ABUNDANT MOISTURE TO THE EAST OF IT. KEPT
POPS LARGELY CONFINED TO CARBON COUNTY THROUGH THE NIGHT AS THE
MODELS DO NOT INDICATE MUCH EASTWARD PROGRESS IN THE UPPER LEVEL
SYSTEM AND ITS ASSOCIATED MOISTURE PLUME. THAT BEGINS TO CHANGE BY
SUN AS A SHORTWAVE PIVOTS NORTHWARD ACROSS SOUTHEAST WY BY MIDDAY
THROUGH THE AFTN. WIDESPREAD RAIN WILL DEVELOP MAINLY TO THE WEST
OF THE LARAMIE RANGE DURING THE MORNING AND THEN WILL SPREAD OVER
PORTIONS OF THE PLAINS OF SOUTHEAST WYOMING THROUGH THE EARLY
EVENING. PW VALUES ARE QUITE HIGH FOR LATE SEP (GENERALLY 0.75-0.9
INCHES) DUE TO THE DEEP MOIST SOUTHERLY FLOW...SO CAN NOT RULE
OUT SOME HEAVY RAIN PRODUCERS. TEMPS WILL BE COOLER ON SUN BY
AROUND 10 DEGREES WITH MORE CLOUD COVER AND PRECIPITATION.

BY MON THE UPPER LOW RAPIDLY LIFTS TO THE NORTHEAST WITH
INCREASING UPPER LEVEL DIFFLUENCE DURING THE AFTN...ESPECIALLY
OVER THE PLAINS. THE GFS SHOWS WIDESPREAD QPF OF OVER 0.5 INCHES
TO THE EAST OF THE LARAMIE RANGE FROM 18Z SUN THRU 06Z MON. THESE
LARGE AMOUNTS MAKE SENSE WITH THE UPPER JET JUST TO THE SOUTH OF
THE AREA AND GREAT VERTICAL ASCENT. CANNOT RULE OUT A FEW STRONGER
STORMS OVER THE PANHANDLE ON MON AFTN...ALTHOUGH THE POTENTIAL
WILL BE LIMITED BY THE ABUNDANT CLOUD COVER AND MARGINAL
INSTABILITY. FRONTAL PASSAGE OCCURS LATE IN THE DAY ON MON WITH
7OOMB TEMPS FALLING TO ABOUT 2C. LIGHT SNOW WILL BE POSSIBLE IN
THE HIGHER ELEVATIONS OF THE SIERRA MADRE AND SNOWY RANGES FROM
THE AFTN THROUGH THE EVENING...ALTHOUGH NOT EXPECTING MUCH MORE
THAN AN INCH DUE TO THE INCREASING SUBSIDENCE BY THAT TIME. THE
FOCUS FROM MON NIGHT THRU TUES MORNING WILL SHIFT TO THE
INCREASING WINDS. THE MODELS INDICATE CYCLOGENESIS OCCURRING BY
LATE MON NIGHT OVER WESTERN SOUTH DAKOTA. 700MB WINDS OFF THE GFS
ARE 50-60 KTS OVER THE PLAINS BY SUNRISE ON TUES SO COULD BE
LOOKING AT LEAST WIND ADVISORY POTENTIAL IN THE PANHANDLE. THE
WIND PRONE AREAS OF SOUTHEAST WY COULD ALSO SEE THE FIRST HIGH
WIND EVENT OF THE SEASON.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 430 PM MDT SAT SEP 27 2014

A COOL PERIOD SHAPING UP FOR TUE-FIR AS A LONGWAVE TROUGH CONSISTING
OF SEVERAL SHORTWAVES SLOWLY SWINGS THRU. ALTHOUGH SMALL CHANCES FOR
PRECIP WILL EXIST PERIODICALLY TUE-THU...THE BEST CHANCES WILL BE NR
THE PINE RIDGE WITH THE FIRST DEPARTING SHORTWAVE ON TUESDAY AND
AGAIN WITH THE 2ND SHORTWAVE THAT PUSHES THRU CWA-WIDE ON WEDNESDAY.
WILL NEED TO KEEP ON EYE ON STRONG WIND POTENTIAL TUESDAY MORNING AS
WELL AS H7 PROGS CLIMB TO NR 50 KNOTS. ITS NOT EXACTLY A
CLIMATOLOGICALLY FAVORABLE FOR STRONG WINDS...BUT NOT OUT OF THE
REALM OF POSSIBILITY EITHER. EACH SHORTWAVE WILL PROVIDE A
REINFORCING SHOT OF COOL AIR...COOLING HIGH TEMPERATURES FROM THE
LOW 60S TUESDAY INTO THE MID/UPPER 50S BY FRIDAY. SNOW-LEVELS WILL
HOVER 9-10 KFT TUESDAY AND WEDNESDAY...DIPPING TO AROUND 8 KFT
THURSDAY MORNING...WHICH SHOULD BE THE LOWEST OF THE PERIOD.
ALTHOUGH SIGNIFICANT SNOW ACCUMULATIONS ARE NOT EXPECTED...
ELEVATIONS ABOVE 8 KFT COULD SEE A SKIFF UP TO SEVERAL INCHES AT THE
HIGHER PEAKS...ESPECIALLY ON WEDNESDAY. ONE FINAL SHORTWAVE DROPS
SOUTHEAST WITHIN THE NW FLOW ON THURSDAY...MAINLY IMPACTING AREAS
FROM THE NRN LARAMIE RANGE EAST ALONG THE PINE RIDGE. FRIDAY LOOKS
DRY AT THIS POINT AND LIKELY STILL COOL AS THE PATTERN TRANSITIONS
FROM CYCLONIC TOWARDS ANTICYCLONIC AHEAD OF WARMING ANTICIPATED NEXT
WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1215 PM MDT SAT SEP 27 2014

VFR CONDITIONS TO PREVAIL AT MOST SITES THROUGH THIS UPCOMING
PERIOD. THE EXCEPTION WILL BE AT KRWL...WHERE ISOLATED CONVECTION
WILL PUSH NORTH OFF OF THE SIERRA MADRE RANGE BETWEEN 21-04Z.
SHOULD ALSO SEE SOME LOWER MVFR CIGS PUSH INTO KRWL AFTER 12Z
SUNDAY AS WELL...AS THE LOW PRESSURE AREA APPROACHES. A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE JUST BEYOND THIS
PERIOD...SUNDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 430 PM MDT SAT SEP 27 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. COOLER
TEMPERATURES ALONG WITH INCREASING MOISTURE WILL CAUSE AFTERNOON
HUMIDITY VALUES TO RISE OVER THE NEXT FEW DAYS. THE ABUNDANT
MOISTURE WILL COMBINE WITH LIFT FROM AN APPROACHING SYSTEM TO
PRODUCE A GOOD CHANCE OF WIDESPREAD WETTING RAINS ON SUNDAY ACROSS
SOUTHEAST WYOMING AND THEN OVER THE PLAINS OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE ON MONDAY. WINDY CONDITIONS
WILL DEVELOP ON TUESDAY...HOWEVER MINIMUM RELATIVE HUMIDITY VALUES
WILL REMAIN ABOVE 35 PERCENT.

&&

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

$$

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






000
FXUS65 KCYS 271815
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1215 PM MDT SAT SEP 27 2014

.SHORT TERM...(TODAY AND SUNDAY)
ISSUED AT 340 AM MDT SAT SEP 27 2014

QUIET WEATHER WITH CLEAR SKIES AND RELATIVELY MILD TEMPERATURES
WERE OBSERVED EARLY THIS MORNING ACROSS SOUTHEAST WYOMING AND
WESTERN NEBRASKA AS A RIDGE AXIS ALOFT BEGINS TO DRIFT EAST INTO
THE GREAT PLAINS. CURRENT IR AND WATER VAPOR SATELLITE IMAGERY
SHOWS A DEEP UPPER LEVEL LOW PUSHING ACROSS CENTRAL
CALIFORNIA...WITH THUNDERSTORM ACTIVITY EXTENDING NORTHWARD INTO
SOUTHERN IDAHO AND NORTHERN UTAH. THIS STORM SYSTEM IS EXPECTED TO
PRODUCE WIDESPREAD RAINFALL AND POSSIBLY MOUNTAIN SNOWFALL ACROSS
THE FORECAST AREA THROUGH MONDAY NIGHT. FOR TODAY...ONE MORE WARM
DAY EXPECTED AS THE UPPER LEVEL LOW WILL TEMPORARILY STALL ACROSS
THE WESTERN GREAT BASIN REGION THROUGH TONIGHT. THIS WILL KEEP
MOST OF THE SHOWERS AND ISOLATED TSTORM ACTIVITY FURTHER TO THE
WEST...WHICH MAY CLIP CARBON COUNTY. KEPT POP BETWEEN 20 TO 30
PERCENT WEST OF THE SNOWY RANGE...AND ACTUALLY LOWERED POP ALONG
THE LARAMIE RANGE LATE TODAY AND TONIGHT. HIGHS WILL REMAIN ABOVE
NORMAL WITH AFTERNOON TEMPS IN THE UPPER 70S TO UPPER 80S.

MODELS SHOW THE UPPER LEVEL LOW MOVING VERY LITTLE ON
SUNDAY...BASICALLY REMAINING OVER THE WESTERN GREAT BASIN.
HOWEVER...THE FIRST SHORTWAVE DISTURBANCE IN ASSOCIATION WITH A
95KT JET MAX WILL LIFT NORTHEASTWARD AROUND THE BASE OF THE LOW BY
SUNDAY AFTERNOON. SCATTERED TO NUMEROUS SHOWERS ARE EXPECTED TO
DEVELOP AND PUSH NORTHEAST THROUGH THE DAY WITH ISOLATED
THUNDERSTORMS POSSIBLE. BELIEVE THIS ACTIVITY WILL HOLD OFF UNTIL
LATE SUNDAY EVENING ACROSS WESTERN NEBRASKA DUE TO DRY AIR ALOFT
AND SOME SUBSIDENCE ON THE WESTERN EDGE OF THE UPPER LEVEL RIDGE
ACROSS THE PLAINS. INCREASED POP BETWEEN 60 TO 80 PERCENT ACROSS
SOUTHEAST WYOMING INTO SUNDAY EVENING. SOME OF THE TSTORMS WILL
PRODUCE GUSTY WINDS AND VERY HEAVY RAINFALL. GENERALLY EXPECT
BETWEEN ONE TENTH TO THREE TENTHS OF AN INCH OF RAIN WITH THIS
INITIAL BAND...BUT SOME OF THE HEAVIER SHOWERS MAY PRODUCE OVER
THREE QUARTERS OF AN INCH OF RAIN LOCALLY.

FOR MONDAY...THE MAIN SYSTEM WILL MOVE ACROSS THE CENTRAL ROCKY
MOUNTAINS AND IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT. WILL
HAVE TO CLOSELY MONITOR THIS SYSTEM FOR THE POTENTIAL OF FLASH
FLOODING AND STRONG THUNDERSTORMS...SINCE MODELS INDICATE THE
UPPER LEVEL LOW BECOMING AN OPEN WAVE NEGATIVELY TILTED TROUGH AS
IT MOVES EASTWARD. THE GFS...ECMWF AND NAM ARE IN PRETTY GOOD
AGREEMENT...SHOWING THE POTENTIAL FOR WIDESPREAD MODERATE TO HEAVY
RAINFALL ALONG WITH RAIN CHANGING TO SNOW IN THE MOUNTAINS. THE
GEM GENERALLY STILL SHOWS A CLOSED LOW MONDAY NIGHT...STALLING
ACROSS WYOMING. AFTER A BRIEF LULL MONDAY MORNING WITH MAINLY
DRIZZLE...LOW STRATUS AND PATCHY FOG...SHOWERS AND TSTORMS WILL
QUICKLY DEVELOP AND INCREASE IN COVERAGE DURING THE AFTERNOON.
INCREASED POP BETWEEN 60 TO 75 PERCENT ACROSS MOST OF THE
AREA. TEMPERATURES WILL BE CLOSER TO NORMAL ON MONDAY AND
GENERALLY IN THE 60S ACROSS SOUTHEAST WYOMING AND LOW TO MID 70S
ACROSS WESTERN NEBRASKA.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM MDT SAT SEP 27 2014

A CHANGE IN THE WEATHER PATTERN WILL MAKE FOR COOLER TEMPERATURES
AND CHANCES FOR PRECIPITATION THROUGH MUCH OF NEXT WEEK. THE UPPER
LEVEL RIDGE WHICH HAS BEEN IN PLACE OVER THE ROCKIES THE LAST
SEVERAL DAYS WILL BE REPLACED BY AN UPPER LEVEL TROUGH. THE MAIN
PIECE OF UPPER LEVEL ENERGY IS FORECAST TO MOVE OVER SOUTHEAST
WYOMING MONDAY NIGHT AND EARLY TUESDAY. SHOWERS AND A FEW
THUNDERSTORMS WILL BE POSSIBLE AS THE WAVE MOVES ACROSS THE AREA.
TEMPERATURES ALOFT WILL GENERALLY BE WARM ENOUGH THAT SNOW WILL NOT
BE MUCH OF A FACTOR...ALTHOUGH THE MOUNTAINS COULD SEE SOME LIGHT
SNOW ACCUMULATIONS WITH A FEW INCHES POSSIBLE BASED ON CURRENT MODEL
RUNS.

SHORTWAVE ENERGY WILL LIFT INTO THE NORTHERN PLAINS LATE TUESDAY AS
A KICKER DROPS OUT OF THE PACIFIC NORTHWEST AND AFTER THAT THE
DETAILS IN THE FORECAST BECOME CONVOLUTED. EXTENDED MODELS ALL HAVE
DIFFERENT IDEAS WITH REGARDS TO TIMING...PLACEMENT AND STRENGTH OF
SHORTWAVE ENERGY TUESDAY THROUGH THURSDAY. SUFFICE IT TO SAY HIGH
TEMPERATURES WILL BE BELOW NORMAL NEXT WEEK WITH THE MEAN UPPER
TROUGH IN PLACE AND NORTHWEST FLOW ALOFT. ISOLATED TO SCATTERED
AFTERNOON RAIN SHOWERS WILL BE POSSIBLE OVER THE PLAINS NEARLY
EVERYDAY AND THERE WILL BE CHANCES FOR LIGHT SNOW ACCUMULATIONS IN
THE MOUNTAINS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1215 PM MDT SAT SEP 27 2014

VFR CONDITIONS TO PREVAIL AT MOST SITES THROUGH THIS UPCOMING
PERIOD. THE EXCEPTION WILL BE AT KRWL...WHERE ISOLATED CONVECTION
WILL PUSH NORTH OFF OF THE SIERRA MADRE RANGE BETWEEN 21-04Z.
SHOULD ALSO SEE SOME LOWER MVFR CIGS PUSH INTO KRWL AFTER 12Z
SUNDAY AS WELL...AS THE LOW PRESSURE AREA APPROACHES. A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE JUST BEYOND THIS
PERIOD...SUNDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 227 AM MDT SAT SEP 27 2014

ONE MORE RELATIVELY DRY DAY EXPECTED ON SATURDAY AHEAD OF A STRONG
UPPER LEVEL LOW MOVING ACROSS CALIFORNIA AND NEVADA. SCATTERED
SHOWERS AND ISOLATED THUNDER WILL DEVELOP OVER CARBON THIS
AFTERNOON...BUT IS NOT EXPECTED TO PUSH EAST OF THE SNOWY RANGE
UNTIL SUNDAY AS THE UPPER LEVEL LOW STALLS OVER THE GREAT BASIN
REGION. MINIMAL FIRE WEATHER CONCERNS THROUGH THIS WEEKEND AND
INTO EARLY NEXT WEEK AS COOLER AIR...WIDESPREAD RAIN...AND
MOUNTAIN SNOWFALL IS EXPECTED SUNDAY THROUGH MONDAY NIGHT.
HUMIDITIES WILL TREND HIGHER EACH DAY...WITH DAYTIME MIN HUMIDITIES
BETWEEN 45 TO 60 PERCENT POSSIBLE ON MONDAY.

&&

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

$$

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







000
FXUS65 KCYS 271815
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1215 PM MDT SAT SEP 27 2014

.SHORT TERM...(TODAY AND SUNDAY)
ISSUED AT 340 AM MDT SAT SEP 27 2014

QUIET WEATHER WITH CLEAR SKIES AND RELATIVELY MILD TEMPERATURES
WERE OBSERVED EARLY THIS MORNING ACROSS SOUTHEAST WYOMING AND
WESTERN NEBRASKA AS A RIDGE AXIS ALOFT BEGINS TO DRIFT EAST INTO
THE GREAT PLAINS. CURRENT IR AND WATER VAPOR SATELLITE IMAGERY
SHOWS A DEEP UPPER LEVEL LOW PUSHING ACROSS CENTRAL
CALIFORNIA...WITH THUNDERSTORM ACTIVITY EXTENDING NORTHWARD INTO
SOUTHERN IDAHO AND NORTHERN UTAH. THIS STORM SYSTEM IS EXPECTED TO
PRODUCE WIDESPREAD RAINFALL AND POSSIBLY MOUNTAIN SNOWFALL ACROSS
THE FORECAST AREA THROUGH MONDAY NIGHT. FOR TODAY...ONE MORE WARM
DAY EXPECTED AS THE UPPER LEVEL LOW WILL TEMPORARILY STALL ACROSS
THE WESTERN GREAT BASIN REGION THROUGH TONIGHT. THIS WILL KEEP
MOST OF THE SHOWERS AND ISOLATED TSTORM ACTIVITY FURTHER TO THE
WEST...WHICH MAY CLIP CARBON COUNTY. KEPT POP BETWEEN 20 TO 30
PERCENT WEST OF THE SNOWY RANGE...AND ACTUALLY LOWERED POP ALONG
THE LARAMIE RANGE LATE TODAY AND TONIGHT. HIGHS WILL REMAIN ABOVE
NORMAL WITH AFTERNOON TEMPS IN THE UPPER 70S TO UPPER 80S.

MODELS SHOW THE UPPER LEVEL LOW MOVING VERY LITTLE ON
SUNDAY...BASICALLY REMAINING OVER THE WESTERN GREAT BASIN.
HOWEVER...THE FIRST SHORTWAVE DISTURBANCE IN ASSOCIATION WITH A
95KT JET MAX WILL LIFT NORTHEASTWARD AROUND THE BASE OF THE LOW BY
SUNDAY AFTERNOON. SCATTERED TO NUMEROUS SHOWERS ARE EXPECTED TO
DEVELOP AND PUSH NORTHEAST THROUGH THE DAY WITH ISOLATED
THUNDERSTORMS POSSIBLE. BELIEVE THIS ACTIVITY WILL HOLD OFF UNTIL
LATE SUNDAY EVENING ACROSS WESTERN NEBRASKA DUE TO DRY AIR ALOFT
AND SOME SUBSIDENCE ON THE WESTERN EDGE OF THE UPPER LEVEL RIDGE
ACROSS THE PLAINS. INCREASED POP BETWEEN 60 TO 80 PERCENT ACROSS
SOUTHEAST WYOMING INTO SUNDAY EVENING. SOME OF THE TSTORMS WILL
PRODUCE GUSTY WINDS AND VERY HEAVY RAINFALL. GENERALLY EXPECT
BETWEEN ONE TENTH TO THREE TENTHS OF AN INCH OF RAIN WITH THIS
INITIAL BAND...BUT SOME OF THE HEAVIER SHOWERS MAY PRODUCE OVER
THREE QUARTERS OF AN INCH OF RAIN LOCALLY.

FOR MONDAY...THE MAIN SYSTEM WILL MOVE ACROSS THE CENTRAL ROCKY
MOUNTAINS AND IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT. WILL
HAVE TO CLOSELY MONITOR THIS SYSTEM FOR THE POTENTIAL OF FLASH
FLOODING AND STRONG THUNDERSTORMS...SINCE MODELS INDICATE THE
UPPER LEVEL LOW BECOMING AN OPEN WAVE NEGATIVELY TILTED TROUGH AS
IT MOVES EASTWARD. THE GFS...ECMWF AND NAM ARE IN PRETTY GOOD
AGREEMENT...SHOWING THE POTENTIAL FOR WIDESPREAD MODERATE TO HEAVY
RAINFALL ALONG WITH RAIN CHANGING TO SNOW IN THE MOUNTAINS. THE
GEM GENERALLY STILL SHOWS A CLOSED LOW MONDAY NIGHT...STALLING
ACROSS WYOMING. AFTER A BRIEF LULL MONDAY MORNING WITH MAINLY
DRIZZLE...LOW STRATUS AND PATCHY FOG...SHOWERS AND TSTORMS WILL
QUICKLY DEVELOP AND INCREASE IN COVERAGE DURING THE AFTERNOON.
INCREASED POP BETWEEN 60 TO 75 PERCENT ACROSS MOST OF THE
AREA. TEMPERATURES WILL BE CLOSER TO NORMAL ON MONDAY AND
GENERALLY IN THE 60S ACROSS SOUTHEAST WYOMING AND LOW TO MID 70S
ACROSS WESTERN NEBRASKA.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM MDT SAT SEP 27 2014

A CHANGE IN THE WEATHER PATTERN WILL MAKE FOR COOLER TEMPERATURES
AND CHANCES FOR PRECIPITATION THROUGH MUCH OF NEXT WEEK. THE UPPER
LEVEL RIDGE WHICH HAS BEEN IN PLACE OVER THE ROCKIES THE LAST
SEVERAL DAYS WILL BE REPLACED BY AN UPPER LEVEL TROUGH. THE MAIN
PIECE OF UPPER LEVEL ENERGY IS FORECAST TO MOVE OVER SOUTHEAST
WYOMING MONDAY NIGHT AND EARLY TUESDAY. SHOWERS AND A FEW
THUNDERSTORMS WILL BE POSSIBLE AS THE WAVE MOVES ACROSS THE AREA.
TEMPERATURES ALOFT WILL GENERALLY BE WARM ENOUGH THAT SNOW WILL NOT
BE MUCH OF A FACTOR...ALTHOUGH THE MOUNTAINS COULD SEE SOME LIGHT
SNOW ACCUMULATIONS WITH A FEW INCHES POSSIBLE BASED ON CURRENT MODEL
RUNS.

SHORTWAVE ENERGY WILL LIFT INTO THE NORTHERN PLAINS LATE TUESDAY AS
A KICKER DROPS OUT OF THE PACIFIC NORTHWEST AND AFTER THAT THE
DETAILS IN THE FORECAST BECOME CONVOLUTED. EXTENDED MODELS ALL HAVE
DIFFERENT IDEAS WITH REGARDS TO TIMING...PLACEMENT AND STRENGTH OF
SHORTWAVE ENERGY TUESDAY THROUGH THURSDAY. SUFFICE IT TO SAY HIGH
TEMPERATURES WILL BE BELOW NORMAL NEXT WEEK WITH THE MEAN UPPER
TROUGH IN PLACE AND NORTHWEST FLOW ALOFT. ISOLATED TO SCATTERED
AFTERNOON RAIN SHOWERS WILL BE POSSIBLE OVER THE PLAINS NEARLY
EVERYDAY AND THERE WILL BE CHANCES FOR LIGHT SNOW ACCUMULATIONS IN
THE MOUNTAINS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1215 PM MDT SAT SEP 27 2014

VFR CONDITIONS TO PREVAIL AT MOST SITES THROUGH THIS UPCOMING
PERIOD. THE EXCEPTION WILL BE AT KRWL...WHERE ISOLATED CONVECTION
WILL PUSH NORTH OFF OF THE SIERRA MADRE RANGE BETWEEN 21-04Z.
SHOULD ALSO SEE SOME LOWER MVFR CIGS PUSH INTO KRWL AFTER 12Z
SUNDAY AS WELL...AS THE LOW PRESSURE AREA APPROACHES. A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE JUST BEYOND THIS
PERIOD...SUNDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 227 AM MDT SAT SEP 27 2014

ONE MORE RELATIVELY DRY DAY EXPECTED ON SATURDAY AHEAD OF A STRONG
UPPER LEVEL LOW MOVING ACROSS CALIFORNIA AND NEVADA. SCATTERED
SHOWERS AND ISOLATED THUNDER WILL DEVELOP OVER CARBON THIS
AFTERNOON...BUT IS NOT EXPECTED TO PUSH EAST OF THE SNOWY RANGE
UNTIL SUNDAY AS THE UPPER LEVEL LOW STALLS OVER THE GREAT BASIN
REGION. MINIMAL FIRE WEATHER CONCERNS THROUGH THIS WEEKEND AND
INTO EARLY NEXT WEEK AS COOLER AIR...WIDESPREAD RAIN...AND
MOUNTAIN SNOWFALL IS EXPECTED SUNDAY THROUGH MONDAY NIGHT.
HUMIDITIES WILL TREND HIGHER EACH DAY...WITH DAYTIME MIN HUMIDITIES
BETWEEN 45 TO 60 PERCENT POSSIBLE ON MONDAY.

&&

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

$$

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








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