711
FXUS65 KTFX 262006
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
106 PM MST SUN JAN 26 2025
KEY MESSAGES
- COLD TEMPERATURES LINGER IN CENTRAL AND SOUTHWEST MONTANA VALLEYS
WHILE THE PLAINS BEGIN TO WARM UP EARLY THIS WEEK.
- BREEZY OVER THE PLAINS THIS WEEK.
- COLDER WITH OPPORTUNITIES FOR SNOW NEXT WEEKEND.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
UPPER LEVEL RIDGING CENTERED JUST OFF THE WEST COAST WILL LARGELY
REMAIN IN PLACE THROUGH MUCH OF THE UPCOMING WEEK THANKS TO A
PERSISTENT CUTOFF UPPER LEVEL LOW ACROSS THE SOUTHWEST CONUS. AS A
RESULT, AN ANTI-CYCLONIC NORTHWESTERLY FLOW WILL REMAIN IN PLACE
ACROSS THE NORTHERN ROCKIES THROUGH MUCH OF THE UPCOMING WEEK. THIS
WILL KEEP THE LARGE SCALE CONCERNS AT A MINIMUM THROUGH MUCH OF THE
WEEK. TEMPERATURES ACROSS THE PLAINS WILL TREND ABOVE AVERAGE
THROUGH THE WEEK, WITH PERSISTENT BREEZY WINDS. IN CENTRAL AND
SOUTHWEST MONTANA VALLEYS, COLD AIR IN PLACE WILL BE A BIT STUBBORN
TO MIX OUT, HENCE A FEW MORE COLD MORNINGS WITH OPPORTUNITIES FOR
FOG WILL BE AROUND.
BY THE END OF THE WEEK THE CUTOFF LOW OVER THE SOUTHWEST CONUS
FINALLY SHIFTS EASTWARD, ALLOWING FOR A PROGRESSION OF WEATHER
SYSTEMS ONCE AGAIN. THE AFOREMENTIONED RIDGE SHIFTS EASTWARD LATE
THURSDAY NIGHT INTO FRIDAY, PASSING EAST BY FRIDAY NIGHT AS A BROAD
UPPER LEVEL TROUGH IS QUICK TO TAKE ITS PLACE ACROSS SOMEWHERE
ACROSS THE WEST. ENSEMBLES ARE IN GOOD AGREEMENT THAT A COLDER
PERIOD WILL MOVE IN THIS WEEKEND, WITH MUCH LOWER CONFIDENCE ON THE
MAGNITUDE OF THE COLD AS WELL AS HOW MUCH SNOW COMES WITH IT.
- FORECAST CONFIDENCE & SCENARIOS:
THE GREATEST UNCERTAINTY OVER THE NEXT FEW DAYS WILL BE FOR
TEMPERATURES ACROSS CENTRAL AND SOUTHWEST MONTANA VALLEYS. WITH
LITTLE IN WAY OF WIND IN THE FORECAST, THE COLD TEMPERATURES TO LOOK
TO HANG AROUND LONGER COMPARED TO OVER THE PLAINS FURTHER NORTH.
LOOKING TOWARD THIS WEEKEND, CLUSTER GUIDANCE DEMONSTRATES WHY THERE
IS GOOD CONFIDENCE FOR COOLER TEMPERATURES, BUT LOWER CONFIDENCE FOR
THE MAGNITUDE OF COLD AS WELL AS ANY PRECIPITATION AMOUNTS. 80% OF
CLUSTER MEMBERS FAVOR TROUGHING OVER OR NEAR THE NORTHERN ROCKIES.
THE MAGNITUDE AND PLACEMENT OF THIS TROUGHING IS HIGHLY UNCERTAIN
HOWEVER, WITH ROUGHLY 60% OF MEMBERS FAVORING A DEEPER, SLOWER
TROUGH ACROSS THE PACIFIC NORTHWEST SUNDAY, 20% FAVORING A SLOWER
BUT LESS AMPLIFIED TROUGH SHUNTED FURTHER NORTH THAN ALL OTHER
MEMBERS, AND ANOTHER 20% FAVORING A FASTER VERSION OF A LESS
AMPLIFIED TROUGH PROGRESSING ACROSS THE NORTHERN ROCKIES. ALL THIS
TO SAY, CONFIDENCE WITH RESPECT TO SPECIFICS IS LOW AT THIS TIME FOR
THIS WEEKEND. -AM
AVIATION
26/18Z TAF PERIOD
PATCHY FOG NEAR KHLN SHOULD GRADUALLY IMPROVE THROUGH EARLY THIS
AFTERNOON, HOWEVER A LINGERING POOL OF COLD AIR AT THE SURFACE
FROM THE HELENA VALLEY SOUTH THROUGH THE GALLATIN VALLEY COULD
LEAD TO SOME PATCHY FOG DEVELOPMENT AGAIN TONIGHT AT KHLN AND
KBZN. OTHERWISE, VFR CONDITIONS PREVAIL ACROSS THE AREA BENEATH A
DRY/STABLE NORTHERLY FLOW ALOFT WITH JUST SOME THIN HIGH CLOUDS AT
TIMES. WEST TO SOUTHWEST SURFACE WINDS INCREASE ACROSS THE NORTH-
CENTRAL MT PLAINS TODAY WITH LIGHT WINDS PREVAILING ACROSS
SOUTHWEST MT VALLEYS. HOENISCH
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 18 37 19 38 / 0 0 0 0
CTB 21 37 21 38 / 0 0 0 0
HLN 4 29 10 32 / 0 0 0 0
BZN -4 27 6 34 / 0 0 0 0
WYS -22 31 -14 37 / 0 0 0 0
DLN 3 27 9 34 / 0 0 0 0
HVR 18 36 17 36 / 0 0 0 0
LWT 19 39 22 42 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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