Area Forecast Discussion Issued by NWS Cheyenne, WY
000
FXUS65 KCYS 131738
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1138 AM MDT MON MAY 13 2013
.UPDATE...
ISSUED AT 1130 AM MDT MON MAY 13 2013
FORECAST IN GOOD SHAPE THROUGH THIS AFTERNOON. MANY AREAS IN THE
NEBRASKA PANHANDLE ARE ALREADY IN THE 80S. STILL SOME MODEL
UNCERTAINTY WITH THE COLD FRONT PROGGED TO MOVE ACROSS THE
PANHANDLE ON TUESDAY. THE NAM IS FASTER AND BRINGS WEAK NORTHERLY
WINDS THROUGH THE REGION BY 18Z TUES...WHEREAS THE GFS WAITS UNTIL
THE EVENING. HOWEVER...EVEN THE SLOWER AND DRIER GFS SHOWS ONLY
10-15 KTS IN THE BOUNDARY LAYER ON TUES AFTN. AT THIS POINT...NOT
PLANNING ON UPGRADING THE FIRE WEATHER WATCH IN THE AFTN PACKAGE
WITH THIS MUCH UNCERTAINTY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 254 AM MDT MON MAY 13 2013
COLD FRONT EXTENDS FROM A SURFACE LOW OVER CENTRAL ALBERTA THIS
MORNING. FRONT EXTENDS FROM KHVR TO THE NORTHERN IDAHO
PANHANDLE...DOWN INTO EASTERN OREGON. AHEAD OF THIS FRONT...700MB
TEMPERATURES ARE AROUND +8 TO +10C ACROSS SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE. VERY WARM TEMPERATURES BEING REPORTED ACROSS
SOUTHEAST WYOMING WITH LOW TO MID 50S AT MOST LOCATIONS IN
SOUTHEAST WYOMING.
700MB TEMPERATURES CONTINUE TO INCREASE TODAY...UP TO +12C THIS
AFTERNOON AS THE UPPER RIDGE AXIS MOVES OVERHEAD. THE WARMEST
TEMPERATURES OF THE YEAR SO FAR ARE ON TRACK TO OCCUR WITH
WIDESPREAD 90S IN THE PANHANDLE AND 80S IN SOUTHEAST WYOMING.
THINK PRECIP WILL BE NONEXISTENT ACROSS MOST AREAS...ONLY AREAS
THAT MAY SEE SOME SHOWERS WOULD BE THE SNOWY AND SIERRA MADRE
RANGES. WINDS LOOK TO REMAIN LIGHT THROUGH THE DAY.
700MB WINDS REALLY BEGIN RAMPING UP THIS EVENING WITH THE GFS
SHOWING 30+ KTS AT 700MBS AT 06Z. LEE SIDE LOW FROM EASTERN MONTANA
EXTENDS DOWN TO THE COLORADO FRONT RANGE. 850MB WINDS IN THE
PANHANDLE FORECAST AS HIGH AS 45KTS ACROSS DAWES AND SIOUX
COUNTIES TONIGHT. WILL LET THE DAY SHIFT TAKE ANOTHER LOOK FOR
POSSIBLE WIND ADVISORIES OUT THERE TONIGHT. ONE IMPORTANT ASPECT
OF THESE WINDS IS THAT THEY WILL KEEP TEMPERATURES UP TONIGHT WITH
WIDESPREAD MID TO UPPER 50 LOWS EXPECTED. POOR HUMIDITY RECOVERIES
CAN BE EXPECTED WITH THESE GUSTY WINDS AND WARM OVERNIGHT LOWS.
WINDS STAY PRETTY STRONG THROUGH THE MORNING HOURS INTO THE
AFTERNOON. GFS SOUNDINGS FOR THE PANHANDLE SHOWING WINDS FROM
600MB AND HIGHER COULD MIX DOWN TO THE SURFACE DURING THE DAY
TUESDAY. COMBINATION OF WARM DOWNSLOPING WINDS AND DRYING WILL
DROP AFTERNOON HUMIDITIES DOWN TO AROUND 10 PERCENT FOR MANY
LOCATIONS TUESDAY AFTERNOON.
FRONT LOOKS TO MOVE INTO THE CWFA ACROSS OUR NORTHERN ZONES BY 00Z
WEDNESDAY AND THROUGH THE CHEYENNE AREA BY 06Z. WINDS BECOME MORE
NORTHEASTERLY AFTER THAT TIME.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 254 AM MDT MON MAY 13 2013
COOLER CONDITIONS EXPECTED FOR WEDNESDAY THOUGH STILL ON THE WARM
SIDE. MAINLY DRY AS WELL EXCEPT OVER SE WYOMING CLOSE TO THE
COLORADO BORDER WHERE A FEW STORMS MAY POP UP IF SUFFICIENT
INSTABILITY DEVELOPS IN COMBINATION WITH A WEAK IMPULSE THAT WILL
MOVE BY. MAINLY DRY AND WARMER THURSDAY AS HEIGHTS RISE AHEAD OF
UPPER TROF THAT WILL MOVE ONSHORE ALONG THE WEST COAST BY LATE IN
THE DAY. FRIDAY THROUGH THE WEEKEND SHOULD SEE A TREND TOWARDS
COOLER TEMPERATURES AND BETTER CHANCES FOR SHOWERS AND A FEW
STORMS AS THE UPPER TROF APPROACHES AND MOVES ACROSS DURING THE
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1130 AM MDT MON MAY 13 2013
VFR CONDITIONS THROUGH THE TAF PERIOD. EXPECT SCATTERED HIGH BASED
CUMULUS TO DEVELOP THIS AFTERNOON. SFC WINDS WILL GENERALLY BE
BELOW 15 KTS THROUGH THE EVENING.
&&
.FIRE WEATHER...
ISSUED AT 254 AM MDT MON MAY 13 2013
LOOK FOR INCREASING TEMPERATURES TODAY WITH AFTERNOON HUMIDITIES
FALLING WELL BELOW 15 PERCENT THIS AFTERNOON. FORTUNATELY...WINDS
WILL BE ON THE WEAK SIDE TODAY. THEY DO START PICKING UP LATE THIS
AFTERNOON AND OVERNIGHT...WHICH WILL RESULT IN POOR OVERNIGHT
HUMIDITY RECOVERIES. BY TONIGHT...A LOW PRESSURE SYSTEM TRACKING
THROUGH MONTANA WILL INCREASE WINDS ACROSS MUCH OF SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE. THESE WINDS WILL CONTINUE INTO
TUESDAY MORNING AND AFTERNOON. WITH VERY WARM TEMPERATURES ONCE
AGAIN TUESDAY AFTERNOON...WINDS FROM 15K FEET OR HIGHER WILL MIX
DOWN TO THE GROUND LEVEL WITH WIND GUSTS IN EXCESS OF 30 MPH AREA
WIDE. DEPENDING ON WHAT THE NEBRASKA PANHANDLE FUELS POC REPORTS
TODAY FOR THEIR FUEL STATUS...WE MAY NEED TO ISSUE A RED FLAG
WARNING FOR ZONES 311-313 IN THE PANHANDLE. FOR NOW...WILL GO
AHEAD AND ISSUE A FIRE WEATHER WATCH FOR THE PANHANDLE ZONES AND
AWAIT FUEL UPDATES LATER TODAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY
AFTERNOON FOR NEZ311>313.
&&
$$
UPDATE...FINCH
SHORT TERM...CLAYCOMB
LONG TERM...RE
AVIATION...FINCH
FIRE WEATHER...CLAYCOMB