Area Forecast Discussion
Issued by NWS Cheyenne, WY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS65 KCYS 052346
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 PM MDT TUE MAY 5 2015

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 318 PM MDT TUE MAY 5 2015

MIDLEVEL CIRCULATION NOTED ON WATER VAPOR AND MOSAIC RADAR IMAGERY
SLOWLY WORKING ITS WAY NORTH OUT OF THE PUEBLO AREA WITH BANDED
RAINS AND ISOLATED THUNDERSTORMS ON THE NORTH SIDE OF THIS
FEATURE EXPECTED TO OVERSPREAD MUCH OF OUR FORECAST AREA OVER THE
NEXT 12-18 HOURS. HIGHEST POPS ARE BEING ADVERTISED ACROSS THE
SOUTHERN AND EASTERN ZONES THROUGH TONIGHT. IN THE VERY NEAR
TERM...UPSLOPE SOUTHEASTERLY LOW LEVEL FLOW HAS INDUCED AREAS OF
DENSE FOG AND DRIZZLE ACROSS LARAMIE COUNTY WYOMING...WITH LOWEST
VISIBILITIES BEING SEEN AROUND AND THE SOUTH AND WEST OF CHEYENNE
IMPACTING INTERSTATES 80 AND 25. EXTENDED THE DENSE FOG ADVISORY
THROUGH 6 PM MDT FOR THESE AREAS...AND EVENING WATCH WILL CONTINUE
TO MONITOR TRENDS. CURRENT THINKING IS THAT WHEN THE RAINS MOVE IN
FROM THE SOUTH LATER THIS EVENING...THAT WILL START TO SHUT THE
FOG PROCESS DOWN A BIT...OR AT LEAST INCREASE VISIBILITIES ABOVE
1/4 MILE.

ON THE LARGER SCALE...MODELS IN FAIR AGREEMENT KEEPING THE
SOUTHWESTERLY UPPER FLOW GOING THROUGH THURSDAY WITH AN INITIAL
SHORTWAVE TRANSITING OUR FORECAST AREA TOMORROW MORNING...EXITING
TO THE EAST IN THE AFTERNOON. THIS WILL BRING A WEAK COLD FRONT
DOWN THE EAST SIDE OF THE DIVIDE TOMORROW...AND THAT SHOULD HELP
FOCUS A LITTLE MORE CONVECTION INTO EARLY AFTERNOON. WE PEGGED
THE HIGHER POPS FOR MOSTLY RAIN/ISOLATED THUNDERSTORMS TOMORROW
MORNING THEN TAPERED POPS DOWN A BIT INTO CHANCE CATEGORY TOMORROW
EVENING...THEN BACK UP AGAIN ON THURSDAY AS ANOTHER SHORTWAVE
EJECTS NORTHEAST ACROSS THE AREA OUT OF THE LARGER UPPER LOW
ACROSS CALIFORNIA.

.LONG TERM...(THURSDAY NIGHT THROUGH NEXT TUESDAY)
ISSUED AT 318 PM MDT TUE MAY 5 2015

WET PATTERN WILL PERSIST ACROSS THE CWA THURSDAY NIGHT THROUGH
MUCH OF SUNDAY WITH SOME LULLS IN THE INTERIM BETWEEN PASSING
SHORTWAVES EJECTING NORTHEAST FROM AN UPPER LOW THAT WILL BE OVER
THE SW CONUS. THIS SYSTEM WILL BE THE MAIN CONCERN OVER THE
WEEKEND AS IT FINALLY MOVES OUT ACROSS THE SRN ROCKYS INTO THE
CENTRAL PLAINS LATER SATURDAY INTO SUNDAY. AS IT DOES SO A LEE
CYCLONE WILL DEEPEN OVER SE COLORADO LATE SATURDAY AND MOVE
NORTHEAST OVER THE CENTRAL PLAINS SUNDAY. THIS WILL DRAW COLDER
AIR SOUTH ACROSS THE CWA SAT NIGHT AND LIKELY CHANGE PCPN OVER TO
SNOW OVER THE MTNS INTO AT LEAST A PART OF THE ADJACENT HIGH
PLAINS. THIS ALONG WITH A HEALTHY BREEZE COULD MAKE FOR QUITE A
PROBLEM SO WILL HAVE TO WATCH CLOSELY OVER THE NEXT FEW DAYS TO
SEE HOW THIS DEVELOPS. REGARDLESS DECENT QPF LOOKING LIKELY OVER
MUCH OF THE CWA AS THIS SYSTEM PASSES ACROSS THE REGION.

SHOULD SEE CLEARING CONDITIONS LATER SUNDAY AS THE SFC/UPPER LOWS
MOVE FARTHER EAST OF THE CWA. SHORT UPPER RIDGING MOVE ACROSS
LATER MONDAY WITH SW FLOW ALOFT RETURNING ON TUESDAY. MONDAY AND
TUESDAY LOOK TO BE MILD AND MAINLY DRY WITH JUST SOME MTN SHOWERS
MAINLY ON TUESDAY WITH A PASSING DISTURBANCE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH NOON WEDNESDAY

FOG HAS MOSTLY LIFTED ACROSS THE AREA...BUT THIS WILL BE TEMPOARY AS
WIDESPREAD IFR OR LIFR CIGS WILL BECOME MORE COMMON BY THIS EVENING
AS A LARGE AREA OF LIGHT TO MODERATE RAIN MOVES ACROSS THE HIGH
PLAINS DUE TO A SURFACE LOW PRESSURE SYSTEM. THE RAIN MAY COME TO AN
END AFTER MIDNIGHT FROM KCYS TO KSNY FOR A TIME...BUT EXPECT FOG TO
REDEVELOP WITH LIFR VIS POSSIBLE.

WINDS WILL GRADUALLY SHIFT INTO THE WEST BY NOON
WEDNESDAY...RESULTING IN SOME SLIGHTLY DRIER AIR MOVING INTO THE
AREA.

&&

.FIRE WEATHER...
ISSUED AT 318 PM MDT TUE MAY 5 2015

WITH A PERSISTENT UPPER LOW PARKED TO THE SOUTHWEST OVER THE 4
CORNERS REGION FOR THE NEXT SEVERAL DAYS...IT APPEARS A FAIRLY
WET WEATHER PATTERN WILL PERSIST FOR MOST PERIODS THROUGH THE
WEEKEND. NOT EXPECTING ANY FIRE WEATHER CONCERNS THROUGH THE
WEEKEND GIVEN THE WET AND COOL PATTERN IN PLACE.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 6 PM MDT THIS EVENING FOR WYZ116>118.

NE...NONE.
&&

$$

SHORT TERM...JG
LONG TERM...RE
AVIATION...TJT
FIRE WEATHER...JG


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.