Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 261841 AAA
AFDCYS

AREA FORECAST DISCUSSION...UPDATED TO REMOVE WY HAZARD
NATIONAL WEATHER SERVICE CHEYENNE WY
1126 AM MDT SUN OCT 26 2014

.UPDATE...
ISSUED AT 955 AM MDT SUN OCT 26 2014

HIGH WINDS AT ARLINGTON ARE THE MAIN CONCERN THROUGH THE EARLY TO
MID AFTERNOON HOURS. WILL CONTINUE THE INHERITED HIGH WIND WARNING
AS-IS. HOWEVER...GUSTS ABOVE 50 MPH HAVE NOT BEEN OBSERVED SINCE
ABOUT 13Z. WINDS ALOFT ARE PROGGED TO DECREASE THROUGH THE DAY
WITH ONLY AROUND 35 KT AVAILABLE TO MIX AT PEAK HEATING. GRADIENTS
ARE ALSO QUITE MARGINAL WITH THE H85 CAG-CPR AROUND 45 METERS PER
THE NAM12...HIGHEST NOW. THAT SAID...POTENTIAL FOR ANY GUSTS ABOVE
58 MPH IS WINDING DOWN. OTHERWISE THE FORECAST LOOKS GOOD. LOWERED
TEMPS SLIGHTLY ALONG AND SOUTHEAST OF A CYS-TOR LINE WITH A DENSE
CIRROSTRATUS SHIELD LIKELY TO INHIBIT SURFACE HEATING. ANY PCPN
CHANCES THROUGH MID AFTN SHOULD BE CONFINED TO THE MOUNTAINS. WILL
ADDRESS THIS FURTHER WITH THE NEXT COMPLETE PACKAGE.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 300 AM MDT SUN OCT 26 2014

FORECAST CHALLENGES DEAL WITH STRONG WINDS AHEAD OF AN APPROACHING
COLD FRONT...FOLLOWED BY POPS AS THIS FRONT MOVES THROUGH THE
AREA.

CURRENTLY...COLD FRONT BEGINNING TO MAKE A PUSH INTO WESTERN
WYOMING EARLY THIS MORNING. MOSAIC RADAR SHOWING PRETTY ACTIVE
WEATHER WITH THE FRONT WITH NUMEROUS LIGHTNING STRIKES BEING
OBSERVED ON THE IDAHO/WYOMING BORDER ALONG THE FRONT. SOUTHEAST
WYOMING AND THE NEBRASKA PANHANDLE PRETTY DRY AT PRESENT...WITH
DEWPOINTS IN THE TEENS AND 20S WEST OF THE LARAMIE RANGE. WINDS
HAVE BEEN ON THE INCREASE OVER CARBON COUNTY THIS MORNING AHEAD OF
THE FRONT...WITH ARLINGTON AND HALLECK RIDGE GUSTING INTO THE LOW
40MPH RANGE. RAWLINS ASOS REPORTING GUSTS TO 35 MPH AS WELL.
SURFACE HIGH PRESSURE OVER EASTERN NEBRASKA THIS MORNING HAS
GIVEN LOCATIONS EAST OF THE LARAMIE RANGE AN EAST TO SOUTHEAST
WIND WITH HIGHER DEWPOINTS...MID 40S BEING REPORTED AT ALLIANCE
AND CHADRON AS OF 1AM.

FOR TODAY...WILL KEEP THE HIGH WIND WARNING GOING FOR THE
ARLINGTON AREA THIS MORNING. LATEST GFS SHOWING A FAVORABLE SETUP
WITH 700MB WINDS INCREASING TO 40-45KTS. LATEST NAM SOUNDINGS ALSO
SHOWING WINDS INCREASING OUT OVER CARBON COUNTY LATER THIS
MORNING...SO CONFIDENCE IS THERE TO KEEP THE WARNING GOING. WINDS
DO BEGIN TO EASE SOME THIS AFTERNOON WITH THE GFS 700MB WINDS
DECREASING TO 35KTS AFTER 18Z AND DOWN TO 30KTS BY 00Z. DAY SHIFT
WILL PROBABLY NEED TO CANCEL THE WARNING EARLIER THAN EXPECTED.

COLD FRONT LOOKS TO MOVE INTO THE CHEYENNE AREA BY LATE AFTERNOON
AROUND 00Z OR SO. PRETTY COLD AIR BEHIND THE FRONT AND THIS COLD
AIR WILL FILTER INTO THE LARAMIE RANGE AND POINTS EAST DURING THE
EVENING HOURS. SHOULD SEE A RATHER RAW EVENING AND OVERNIGHT
PERIOD AS 700MB TEMPERATURES FALL TO -5 TO -8C ACROSS ALL BUT
EXTREME SOUTHERN PANHANDLE BY 12Z MONDAY.

ONE OTHER NOTE FOR TONIGHT/MONDAY MORNING...THE GFS...ECMWF AND
NAM ARE ALL FORECASTING SOME MID LEVEL FRONTOGENESIS ACROSS
EXTREME SOUTHEAST WYOMING AND CENTRAL THROUGH SOUTHERN PANHANDLE
THIS EVENING. ECMWF AND NAM MOST BULLISH WITH PRECIP
AMOUNTS...ROUGHLY .25 TO .4 INCHES QPF THROUGH 12Z MONDAY. WENT
AHEAD AND INCREASED POPS MORE TO THE ECMWF/NAM SOLUTIONS AND DAY
SHIFT WILL PROBABLY WANT TO INCREASE BASED ON THE 12Z MODEL RUNS.
AS FOR PRECIP TYPE...MOSTLY RAIN EAST OF THE LARAMIE RANGE. RAIN
WEST...TURNING TO SNOW THIS EVENING AS THE COLDER AIR MOVES IN
BEHIND THE FRONT.

A RAW DAY FOR MOST AREAS MONDAY AS 700MB TEMPERATURES REMAIN IN
THE -5 TO -7C RANGE THROUGH THE DAY. TRENDED AFTERNOON HIGHS DOWN
MORE TOWARDS THE NAM FORECAST...WILL PROBABLY NEED TO BE COLDER.
AFTERNOON HIGHS WILL STRUGGLE TO GET OUT OF THE 40S FOR MOST AREAS
IN SOUTHEAST WYOMING. NORTHWEST WINDS GUSTING TO 30 AND 35 MPH
WILL MAKE FOR AN EVEN COLDER DAY.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 138 AM MDT SUN OCT 26 2014

TUESDAY NIGHT...BREEZY AND RELATIVELY MILD NIGHT WITH BRISK
NORTHWEST FLOW ALOFT.

WEDNESDAY...PASSAGE OF DRY SHORTWAVE TROUGH ALOFT. WARMER DAY DUE TO
DOWNSLOPE WARMING.

THURSDAY...SLIGHTLY COOLER DAY IN MOST LOCALES...DESPITE RIDGING
ALOFT MOVING OVERHEAD...WITH COOLER UPSLOPE EAST WINDS.

FRIDAY...RIDGE ALOFT MOVES TO OUR EAST...AND WITH SOUTHWEST FLOW
ALOFT...DECENT SURFACE LEE TROUGHING DEVELOPS PRODUCING A BREEZY TO
WINDY AND MILD HALLOWEEN DAY...PLEASANT FOR OUTDOOR ACTIVITIES.

SATURDAY...WITH SHORTWAVE TROUGH APPROACHING...OUR COUNTIES WILL BE
IN THE WARM SECTOR AHEAD OF THE NEXT COLD FRONT...THUS PRODUCING A
MILD AND DRY DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1120 AM MDT SUN OCT 26 2014

VFR CONDITIONS WILL PREVAIL THIS AFTERNOON WITH GRADUALLY LOWERING
AND THICKENING CLOUDS AHEAD OF A COLD FRONT. WESTERLY WINDS WILL BE
STRONGEST ACROSS SOUTHEAST WY WITH GUSTS OF 30-45 KT...ESPECIALLY
INVOF OF MOUNTAIN WAVE ACTIVITY. ELSEWHERE...GUSTS OF 20-30 KT ARE
EXPECTED. CELINGS WILL LOWER TO MVFR TONIGHT SOUTH OF A RAWLINS TO
ALLIANCE LINE ASSOCIATED WITH SHOWER ACTIVITY. WINDS DIMINISH THIS
EVENING BUT INCREASE ONCE AGAIN AFTER A COLD FRONTAL PASSAGE LATER
TONIGHT WITH GUSTS OF 25-35 KT THROUGH MONDAY MORNING.

&&

.FIRE WEATHER...
ISSUED AT 300 AM MDT SUN OCT 26 2014

ANOTHER WINDY DAY EXPECTED FOR SUNDAY AS COLD FRONT BEGINS TO MOVE
INTO THE AREA FROM WEST TO EAST THROUGH THE AFTERNOON HOURS. THIS
FRONT WILL BRING INCREASING CHANCES FOR MEASURABLE RAINFALL
BEGINNING OUT WEST IN THE MOUNTAINS OF CARBON COUNTY. WETTING RAIN
CHANCES INCREASE FOR THE LARAMIE RANGE AND POINTS EAST MONDAY
MORNING. COLDER TEMPERATURES WILL RESULT IN MINIMAL FIRE WEATHER
CONCERNS MONDAY INTO THE MIDDLE OF NEXT WEEK.

&&

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

NE...NONE.
&&

$$

UPDATE...HAMMER
AVIATION...JAMSKI
SHORT TERM/FIRE WEATHER...CLAYCOMB
LONG TERM...RUBIN



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