227
FXUS65 KBYZ 191737
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
1037 AM MST THU DEC 19 2024
KEY MESSAGES
- GUSTY NW WINDS WILL GRADUALLY DIMINISH OVER THE AREA TODAY.
- ABOVE NORMAL TEMPERATURES. OCCASIONAL CHANCES OF LIGHT
PRECIPITATION THROUGH THE MIDDLE OF NEXT WEEK. ALMOST DAILY
CHANCES FOR WINDS OVER 50MPH IN WESTERN FOOTHILLS STARTING
SUNDAY.
UPDATE
SEE UPDATED AVIATION DISCUSSION BELOW.
DISCUSSION
TODAY THROUGH FRIDAY NIGHT...
A STRONG AND COMPACT WAVE WAS SLIDING EAST INTO NORTH DAKOTA
EARLY THIS MORNING, WITH AN ASSOCIATED COLD FRONT CONTINUING TO
DROP THROUGH THE AREA. EASTERN AREAS HAD WARMED INTO THE UPPER 30S
TO 40S AHEAD OF THE FRONT, BUT HAVE NOW DROPPED INTO THE 20S
BEHIND THE FRONT. STRONG WESTERLY WINDS HAVE BEEN GRADUALLY
DECREASING OVER WESTERN AND CENTRAL AREAS, WHILE EASTERN AREAS CAN
EXPECT STRONG NW WINDS TO CONTINUE A WHILE LONGER, GUSTING INTO
THE 50-60 MPH RANGE. HAVE GONE AHEAD AND EXPIRED THE HIGH WIND
WARNINGS OVER PORTIONS OF THE WEST AND CENTRAL ZONES, AND
CANCELLED THE WIND ADVISORY FOR THE LIVINGSTON AREA AND BEARTOOTH
FOOTHILLS, WITH WINDS DECREASING THERE. THE HIGH WIND WARNING FOR
CUSTER, FALLON, POWDER RIVER AND CARTER COUNTIES EXPIRES AT 5AM.
MAINLY DRY CONDITIONS CAN BE EXPECTED ACROSS THE AREA TODAY, WITH
NW WINDS GRADUALLY DIMINISHING OVER THE EAST. HIGH PRESSURE
BUILDING IN FROM THE WEST WILL KEEP WESTERN AND CENTRAL AREAS WARM
WITH HIGHS IN THE 40S, WHILE EASTERN AREAS WILL BE COOL, WITH
HIGHS IN THE MIDDLE TEENS TO 20S, COLDEST NEAR BAKER. A SHORTWAVE
MOVING ACROSS THE MT/CANADA BORDER TONIGHT WILL CAUSE PRESSURE
GRADIENTS TO TIGHTEN ALONG THE WESTERN FOOTHILLS, WITH INCREASING
WINDS ALOFT. SW WINDS WILL INCREASE IN THE LIVINGSTON FACILITY,
BUT ARE EXPECTED TO REMAIN BELOW 50 MPH AT THIS TIME (LESS THAN
50% CHANCE). THE WEAK WAVE WILL DROP SOUTHEAST THROUGH NE MT INTO
THE DAKOTAS ON FRIDAY, KEEPING THE EAST ON THE COOL SIDE, BUT
WITH LITTLE IMPACT TO THE REST OF THE AREA BESIDES INCREASE
BREEZINESS. HIGH TEMPERATURES WILL RANGE FROM THE 40S AND 50S OVER
WESTERN AND CENTRAL AREAS, TO THE LOWER 30S OVER THE FAR EAST. STP
SATURDAY THROUGH THURSDAY...
THE LONG TERM WILL SEE PERSISTENT ABOVE AVERAGE 500MB HEIGHTS
WITH OCCASIONAL SHORTWAVE TROUGHS MOVING THROUGH. THIS WILL LEAD
TO WARM TEMPERATURES IN THE 40S TO LOW 50S AND GENERALLY DRY
CONDITIONS.
THE FIRST WAVE WILL MOVE IN SUNDAY BRINGING LOW (30%)
PRECIPITATION CHANCES. DUE TO THE WARM TEMPERATURES, SNOW WOULD
LIKELY BE LIMITED TO THE HIGH TERRAIN WITH RAIN TO MIXED
PRECIPITATION FOR THE LOWER ELEVATIONS. WPC CLUSTERS ARE IN GOOD
AGREEMENT IN KEEPING ANY PRECIPITATION FROM THIS LIGHT, WITH ALL
CLUSTERS SHOWING LESS THAN 0.06 INCHES.
A MORE SIGNIFICANT TROUGH IS POSSIBLE THE MIDDLE OF NEXT WEEK.
THIS IS SEEN IN THE DETERMINISTIC MODELS AS WELL AS ABOUT 40% OF
THE WPC CLUSTERS. NOT MUCH IS KNOWN ABOUT THIS SYSTEM BUT NBM IS
CURRENTLY GIVING A 10-30% CHANCE FOR GREATER THAN 0.1 INCHES OF
PRECIPITATION. TEMPERATURES WOULD LIKELY KEEP THIS AS MOSTLY RAIN
FOR THE LOWER ELEVATIONS BUT CANT SAY MUCH AT THIS POINT. WILL
HAVE TO KEEP AN EYE ON THIS DUE TO THE POSSIBILITY OF INCREASED
IMPACTS FOR CHRISTMAS TRAVEL.
STARTING SUNDAY, STRONG WIND WILL BE AN ALMOST DAILY OCCURRENCE
FOR THE WESTERN FOOTHILLS. PERSISTENT WESTERLY 700MB WINDS WILL
CREATE LEE SIDE TROUGHING. THIS WILL HELP CREATE A PERSISTENT
STRONG IDAHO FALLS TO LEWISTOWN PRESSURE GRADIENT WITH THE
DETERMINISTIC GFS CURRENTLY SHOWING THE GRADIENT REMAINING ABOVE
10MB THROUGH THE WEEK. 700MB WINDS MAY NOT ALWAYS BE FAVORABLE
HOWEVER WHICH MAY BRING SOME BREAKS. TORGERSON
AVIATION
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. WINDS
WILL BE LIGHT ACROSS THE REGION TODAY WITH THE EXCEPTION OF KLVM
THIS EVENING. SW WINDS ARE EXPECTED TO GUST TO 35-45 KTS THIS
EVENING THROUGH THE EARLY AFTERNOON FRIDAY. TS
PRELIMINARY POINT TEMP/POPS
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 042 025/052 032/053 037/051 029/049 029/049 033/046
0/U 00/B 00/B 22/W 01/B 01/B 32/W
LVM 047 032/054 033/054 035/047 029/047 030/051 030/044
0/B 00/N 00/B 41/N 02/W 02/W 52/W
HDN 038 020/049 025/051 030/050 024/049 026/049 029/046
0/U 00/B 00/B 23/W 01/B 00/B 33/W
MLS 021 011/038 020/043 025/043 024/044 025/044 027/042
0/U 00/B 00/B 13/W 00/U 00/U 22/W
4BQ 032 017/044 026/050 029/046 026/046 028/049 030/044
0/U 00/B 00/U 12/W 00/U 00/U 22/W
BHK 015 002/030 016/043 022/040 021/041 022/043 023/039
0/N 00/E 00/B 02/W 00/U 00/U 11/E
SHR 042 021/054 027/056 030/050 024/049 025/052 027/046
0/U 00/B 00/U 12/W 01/B 00/B 33/W
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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