High Wind in Wyoming, February 16, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
434 AM MST FRI FEB 16 2007

.SHORT TERM...VALID FOR TDY AND SAT...

COMPLICATED WEATHER SCENARIO TAKING SHAPE THIS MORNING. SHORTWAVE
ENERGY AND WARM ADVECTION WERE PRODUCING RAIN OVER PORTIONS OF THE
FORECAST AREA EARLY THIS MORNING...MAINLY OVER THE EASTERN HALF OF
THE AREA. WINDS HAVE INCREASED OVER THE ENTIRE REGION IN LAST
COUPLE OF HOURS AND HAVE ALREADY REACHED HIGH WIND WARNING SPEEDS
IN A FEW LOCATIONS. HAVE BEEN KEEPING A CLOSE EYE ON WINDS IN KLVM
WHERE WIND ADVISORY WAS IN EFFECT. MODEL DATA INDICATED THAT AIRMASS
WILL DESTABILIZE THROUGH 12Z WHEN STRONGEST WINDS WILL MIX DOWN
INTO FAVORED GAP FLOW AREAS RESULTING IN WIND SPEEDS OCCASIONALLY
REACHING HIGH WIND CRITERIA (SUSTAINED OF AT LEAST 50 MPH WITH
GUSTS TO AT LEAST 75 MPH). LIVINGSTON DID HAVE A GUST TO 80 MPH
JUST AFTER 3 AM. MODEL DATA SUGGESTS THAT CORE OF STRONGEST 700 MB
WINDS WILL MOVE S OF THE FORECAST AREA LATER THIS MORNING SO WOULD
NOT EXPECT THESE VERY STRONG WINDS TO PERSIST INTO THE LATE
MORNING. WILL HANDLE STRONGER GUSTS WITH NOWCAST AND CONTINUE THE
WIND ADVISORY OVER KLVM AND NYE.

ELSEWHERE...THE HIGH WIND WARNING WAS IN GOOD SHAPE DUE TO GOOD
MIXING DOWN OF STRONG WINDS ALOFT. WITH STRONGEST WINDS MOVING S OF
AREA LATER THIS MORNING...MAY BE ABLE TO CANCEL THIS HIGHLIGHT
EARLY. WILL LET LATER SHIFTS MONITOR THE SITUATION.

TEMPERATURES WERE IN THE 40S OVER MOST OF THE FORECAST AREA EARLY
THIS MORNING. GFS AND WRF SHOWED THAT COLD ADVECTION WILL NOT
OCCUR UNTIL LATE THIS MORNING WHEN A COLD FRONT WILL DROP S INTO THE
AREA. THEREFORE PRECIP TYPE WILL BE RAIN IN MANY AREAS EARLY THIS
MORNING. EXPECT E ZONES TO HAVE ALL SNOW BY THIS AFTERNOON. DUE TO
THE COLD GROUND...MENTIONED A SLIGHT CHANCE OF FREEZING RAIN EARLY
IN THE E. PORTIONS OF CENTRAL AND W ZONES SHOULD MIX WITH SNOW
THIS AFTERNOON DUE TO 850 MB TEMPS FALLING BELOW ZERO AFTER 18Z.
GFS HAD BETTER HANDLE THAN WRF ON PRECIP POTENTIAL TODAY DUE TO
THE GFS CAPTURING A VORT LOBE PRODUCING COOLING CLOUD TOPS OVER
NORTH CENTRAL MT EARLY THIS MORNING. WRF DID NOT SHOW THIS
FEATURE. BASED ON GFS...WENT WITH CATEGORICAL POPS E TODAY. ONLY
CHANGE TO BLIZZARD WARNING WAS TO PUSH BACK START TIME TO
17Z...WHEN SNOW WILL START TO MIX WITH THE RAIN. WILL PROBABLY NOT
HAVE MUCH SNOW BLOWING UP OFF THE GROUND THIS MORNING DUE TO THE
RAIN AND TEMPS IN THE 40S. OTHER CHANGE TO POPS TODAY WAS TO RAISE
THEM TO LIKELY IN THE NW MOUNTAINS DUE TO GOOD STREAM OF VORTICITY
AND MOISTURE OVER THIS AREA.

HIGH TEMPERATURES WILL LIKELY OCCUR IN THE MORNING...ESPECIALLY
EAST. HOWEVER...DO NOT EXPECT MUCH OF A TEMP DROP OVER CENTRAL AND
W AS COLD ADVECTION WILL NOT BE THAT STRONG. SO...MAY HAVE FAIRLY
STEADY TEMPS CENTRAL AND W. RAISED HIGH TEMPS A LITTLE TO REFLECT
TRENDS EARLY THIS MORNING.

MODELS SHOWED PRECIP LINGERING IN THE FAR E THIS EVENING SO RAISED
POPS THERE. LIFT FROM VORTICITY COMBINED WITH N TO NW FLOW AND
MOISTURE WILL BRING LIKELIHOOD OF PRECIP TO KSHR THIS EVENING AS
WELL. LIKELY POPS OVER BIG HORNS WERE IN GOOD SHAPE. AIRMASS DRIED
OUT IN THE W AFTER 06Z SO LOWERED POPS THERE. NO CHANGES TO MIN TEMPS.

FOR SAT...ADDED LOW POPS TO THE NE IN THE MORNING DUE TO DEPARTING
VORTICITY AND MOISTURE. MAX TEMPS LOOKED FINE AND REFLECTED WARMER
CONDITIONS IN DOWNSLOPE AREAS WITH COOLER CONDITIONS E WHERE
INVERSIONS WILL PERSIST THROUGH THE DAY. NO CHANGES TO DRY SAT
NIGHT FORECAST AS UPPER RIDGE MOVES OVERHEAD. ARTHUR

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

UPPER RIDGE ON SUNDAY TO GIVE WAY TO A WEAK TROUGH ON MONDAY
BEFORE UNSETTLED SOUTHWESTERLY FLOW ALOFT SETS UP DURING THE
MIDDLE OF NEXT WEEK. THE RIDGE ON SUNDAY WILL BRING WARM
TEMPERATURES AND DRY WEATHER TO THE FORECAST AREA AND MADE NO
CHANGES TO THE PREVIOUS FORECAST CONCERNING TEMPS OR POPS. WEAK
TROUGH ON MONDAY FORECAST BY THE MODELS TO BE A LITTLE DRIER AND
A LITTLE FASTER THAN PREVIOUS RUNS...BUT STILL DRAGS SOME WAVE
ENERGY THROUGH THE CWA LATE IN THE DAY. HAVE DECIDED TO LEAVE
SLIGHT CHANCE POPS AS THEY ARE PER COORDINATION WITH SURROUNDING
OFFICES AND WILL GIVE THE MODELS A LITTLE MORE TIME TO BECOME
MORE CONSISTENT WITH THE TIMING AND MOISTURE ASSOCIATED WITH THIS
FEATURE. SHORTWAVE RIDGE OVER THE AREA TUESDAY FOR A DRY AND
SLIGHTLY WARMER DAY THAN MONDAY...WITH SOUTHWEST FLOW ALOFT
DEVELOPING DURING THE DAY ON WEDNESDAY AND REMAINING OVER THE
AREA THROUGH THE END OF NEXT WEEK. THIS SHOULD RESULT IN MILD
TEMPERATURES AT OR SLIGHTLY ABOVE NORMAL...WITH CHANCES FOR
PRECIPITATION IN THE WESTERN ZONES EVERY PERIOD FROM WEDNESDAY
THROUGH FRIDAY NIGHT. MACZKO

&&

.AVIATION...

VERY STRONG WINDS WILL CONTINUE ACROSS THE ENTIRE AREA THROUGH
LATE THIS AFTERNOON. WEST TO NORTHWEST WINDS OF 30 TO 45 MPH WITH
GUSTS TO 65 MPH CAN BE EXPECTED ACROSS THE ENTIRE AREA...WITH
SLIGHTLY HIGHER WINDS IN THE LIVINGSTON AREA AND IN THE BEARTOOTH
FOOTHILLS. IN ADDITION TO WINDS...EASTERN MONTANA WILL SEE A MIX
OF RAIN AND FREEZING RAIN EARLY THIS MORNING...BEFORE
PRECIPITATION CHANGES TO SNOW. THIS SNOW WILL COMBINE WITH STRONG
WINDS TO PRODUCE BLIZZARD CONDITIONS ESPECIALLY IN AREAS NEAR AND
TO THE SOUTH AND EAST OF KMLS. MACZKO

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SAT     SUN     MON     TUE     WED     THU
-------------------------------------------------------
BIL 046 020/043 026/046 026/042 024/045 027/045 024/038
    4/O 10/N    00/U    02/W    00/B    02/W    22/O
LVM 043 023/045 035/048 026/041 024/044 028/045 025/038
    4/R 30/N    00/N    03/W    01/B    12/W    22/O
HDN 042 022/045 014/047 026/040 021/046 022/046 020/041
    4/O 10/B    00/U    02/W    10/B    01/B    11/B
MLS 041 017/033 015/038 018/039 017/040 018/041 020/034
    8/O 30/B    00/U    00/B    20/B    00/B    00/B
4BQ 038 021/039 023/046 024/039 020/045 021/043 019/043
    6/O 20/B    00/U    00/B    20/B    00/B    00/B
BHK 036 014/030 013/035 017/035 015/036 016/040 018/032
    8/O 72/J    00/U    00/B    20/B    00/B    00/B
SHR 050 018/042 011/042 024/043 017/042 018/042 016/040
    5/O 60/B    00/U    01/B    20/B    01/B    11/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...HIGH WIND WARNING IN EFFECT UNTIL 6 PM MST THIS AFTERNOON FOR
      ZONES 28>31-34-35-38-39-41-42-56>58-63.
     BLIZZARD WARNING IN EFFECT FROM 10 AM THIS MORNING TO 11 PM
      MST THIS EVENING FOR ZONES 32-33-36-37.
     WIND ADVISORY IN EFFECT UNTIL 6 PM MST THIS AFTERNOON FOR
      ZONES 65-66.
WY...HIGH WIND WARNING IN EFFECT UNTIL 6 PM MST THIS AFTERNOON FOR
      ZONE 99.

&&

WEATHER.GOV/BILLINGS

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE BILLINGS MT
452 AM MST FRI FEB 16 2007

MTZ028>031-034-035-038>042-056>058-063>068-WYZ098-099-171200-
SOUTHERN WHEATLAND-MUSSELSHELL-TREASURE-NORTHERN ROSEBUD-
NORTHERN STILLWATER-YELLOWSTONE-SOUTHERN BIG HORN-EASTERN CARBON-
NORTHERN PARK-NORTHERN SWEET GRASS-GOLDEN VALLEY-
RED LODGE FOOTHILLS-NORTHERN BIG HORN-SOUTHERN ROSEBUD-JUDITH GAP-
PARADISE VALLEY-LIVINGSTON AREA-BEARTOOTH FOOTHILLS-
ABSAROKA/BEARTOOTH MOUNTAINS-CRAZY MOUNTAINS-
NORTHEAST BIG HORN MOUNTAINS-SHERIDAN FOOTHILLS-
452 AM MST FRI FEB 16 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
MONTANA...SOUTH CENTRAL MONTANA...SOUTHEAST MONTANA AND NORTH
CENTRAL WYOMING.

.DAY ONE...TODAY AND TONIGHT
WEST TO NORTHWEST WINDS OF 30 TO 45 MPH WITH GUSTS TO 65 MPH WILL
BE LIKELY ACROSS THE AREA TODAY. SLIGHTLY HIGHER WINDS WILL BE
POSSIBLE AT TIMES IN THE LIVINGSTON AREA AND THE BEARTOOTH
FOOTHILLS...ESPECIALLY NEAR NYE.

THESE STRONG WINDS WILL COMBINE WITH SNOW SHOWERS AND SNOW
ALREADY ON THE GROUND TO PRODUCE AREAS OF BLOWING SNOW...REDUCING
VISIBILITIES TO UNDER ONE MILE AT TIMES. WINDS AND SNOW ARE
EXPECTED TO DIMINISH BY EARLY THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

MTZ032-033-036-037-171200-
CUSTER-FALLON-POWDER RIVER-CARTER-
452 AM MST FRI FEB 16 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST
MONTANA.

.DAY ONE...TODAY AND TONIGHT

RAIN SHOWERS OVER THE AREA MAY MIX WITH FREEZING RAIN AT TIMES
THROUGH THIS MORNING...WITH PRECIPITATION EXPECTED TO CHANGE TO
ALL SNOW BEFORE NOON. SNOW WILL CONTINUE THROUGH THE
AFTERNOON...WITH ACCUMULATIONS OF 2 TO 4 INCHES EXPECTED.

IN ADDITION TO SNOW...VERY STRONG NORTHWEST WINDS OF 30 TO 45 MPH
WITH GUSTS TO 60 MPH WILL BE POSSIBLE THROUGHOUT THE DAY. THESE
WINDS WILL COMBINE WITH SNOW TO PRODUCE AREAS OF BLOWING AND
DRIFTING SNOW...CREATING BLIZZARD-LIKE CONDITIONS AT TIMES. SNOW
AND VERY STRONG WINDS ARE EXPECTED TO DIMINISH THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.