Area Forecast Discussion
Issued by NWS Billings, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 KBYZ 180848
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
248 AM MDT SAT OCT 18 2014

.SHORT TERM...VALID FOR TDY AND SUN...

SEVERAL MINOR TWEAKS TO THE SHORT TERM FORECAST THIS
MORNING...MOSTLY BASED ON WHAT HAVE SEEN THE PAST FEW DAYS...AND
WHAT IS OCCURRING NOW. MODELS REMAIN IN GOOD AGREEMENT THROUGH THE
PERIOD...FAVORING MAINLY WARM AND DRY CONDITIONS ACROSS THE
REGION AS AN UPPER LEVEL RIDGE DOMINATES THE PATTERN.

GREATEST CHANGES CENTERED AROUND SHORTWAVE PUSHING THROUGH THE
REGION TODAY. MODELS CONTINUE TO POINT TO DRY PASSAGE ACROSS THE
REGION...BUT A LINE OF SHOWERS HAVE DEVELOPED THIS MORNING IN THE
WEST...EXTENDING NORTH TO SOUTH THROUGH THE STATE. THIS WAVE
SHOULD IMPACT OUR WESTERN MOUNTAINS MID TO LATE MORNING...AND SEE
NO REASON WHY THERE WOULD BE NO SHOWER ACTIVITY IN THE HIGH
TERRAIN. CONVERSELY...THE PLAINS DO APPEAR TO BE TOO DRY TO
SUPPORT ANYTHING MOVING OFF THE MOUNTAINS. ADDITIONALLY...THE WAVE
FLATTENS THE RIDGE...THEREBY INCREASING DOWNSLOPE FLOW AND
OVER THE PLAINS...FURTHER SUPPRESSING DEVELOPMENT IN THE PLAINS.
HAVE INTRODUCED ISOLD POPS FOR THE HIGH TERRAIN THIS MORNING AND
AFTERNOON...BUT HAVE KEPT PLAINS DRY EXCEPT FOR VERY NEAR THE
MOUNTAINS. THE UPPER LEVEL RIDGE RE-AMPLIFIES OVERNIGHT...AND
SUNDAY...RESULTING IN ANOTHER DRY DAY FOR SUNDAY.

AS FOR TEMPS...EXPECT TO SEE TEMPS WELL ABOVE SEASONAL AVERAGE
BOTH TODAY AND SUNDAY. DOWNSLOPE FLOW WILL HELP THINGS WARM UP A
BIT MORE TODAY EVEN THOUGH SHORTWAVE WILL BRING A BIT OF COOLER
AIR AND CLOUD COVER TO THE REGION THIS MORNING. RIDGE REDEVELOPS
OVERNIGHT AND THROUGH THE DAY SUNDAY. ADDITIONALLY...IN RECENT
DAYS WE HAVE BEEN OVERSHOOTING GUIDANCE WITH OUR DAYTIME
HIGHS...WHETHER DUE TO STRONGER RIDGING THAN EXPECTED OR DRY AIR
WARMING MORE READILY. HAVE RAISED HIGH TEMPS SLIGHTLY FOR BOTH
TODAY AND SUNDAY. HAVE ALSO COOLED OVERNIGHT LOWS IN AND AROUND
KLVM...UNDERCUTTING GUIDANCE BY A FEW DEGREES...BASED PARTLY ON
RAPID COOLING OF PAST COUPLE OF NIGHTS. AAG
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...

QUIET WEATHER WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH
NEXT WEEK. THE ONLY CHANCE OF SHOWERS IS TIED TO A WEAK AND
SPLITTING SHORTWAVE WHICH WILL IMPACT OUR CWA TUESDAY AFTERNOON
INTO EARLY WEDNESDAY. TIMING APPEARS A BIT FASTER WITH THIS
ENERGY...WITH SOME ASCENT IN OUR WEST BY TUESDAY AFTERNOON...SO
HAVE EXPANDED ISOLATED POPS IN OUR WEST DURING THIS PERIOD.
OTHERWISE WE SHOULD SEE SUBSIDENCE SPREAD IN OVERNIGHT AND HAVE
TRENDED POPS DOWN FOR WEDNESDAY. MODEST COLD ADVECTION WILL GIVE
US SOME INCREASED W-NW WIND TUESDAY AFTERNOON AND NIGHT...BUT BY
THURSDAY WE WILL SEE PRESSURE FALLS IN CENTRAL MT AND DECREASED
WIND.

RIDGING WITH ABOVE NORMAL HEIGHTS WILL OTHERWISE DOMINATE OUR
WEATHER NEXT WEEK. ECMWF/CANADIAN ARE A BIT MORE AMPLIFIED THAN
THE GFS WITH THE WESTERN CONUS RIDGE TOWARD THE END OF NEXT
WEEK...BUT ALL MODELS KEEP ANY PACIFIC MOISTURE PLUME TO OUR NW.
THUS HIGH CONFIDENCE IN A DRY FORECAST FOR WEDNESDAY NIGHT THROUGH
FRIDAY. IT SHOULD BE POINTED OUT THAT MODEL DIFFERENCES EXIST IN
THE PACIFIC NEXT WEEK...INCLUDING THE EVOLUTION OF HURRICANE ANA
NEAR HAWAII...SO IT WOULD BE PRUDENT TO KEEP WATCH OF THE ACTIVITY
UPSTREAM OVER THE COMING DAYS.

FOR ANYONE READY FOR A PATTERN CHANGE TO BELOW NORMAL TEMPS...BE
PATIENT. WE ARE NOT SEEING ANY SIGNS OF A SHIFT IN THE NEXT WEEK
TO 10 DAYS...BUT COLD AIR IS BUILDING IN THE HIGHER LATITUDES.

JKL
&&

.AVIATION...

SCATTERED TO BROKEN MID AND HIGH CLOUD CAN BE EXPECTED ACROSS THE
REGION TODAY...AND A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
MOUNTAINS. OTHERWISE...VFR FLIGHT CONDITIONS WILL PREVAIL THROUGH
TONIGHT. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SUN     MON     TUE     WED     THU     FRI
-------------------------------------------------------
BIL 074 044/072 046/075 049/074 046/066 044/071 047/069
    0/B 00/U    00/U    01/B    21/B    00/U    11/U
LVM 071 038/071 039/073 046/071 041/063 040/067 046/065
    2/T 00/U    00/U    02/W    21/B    00/U    11/B
HDN 075 042/073 042/076 044/076 043/067 039/072 042/070
    0/B 00/U    00/U    00/U    21/B    00/U    00/U
MLS 072 043/071 043/075 044/075 045/066 041/070 043/069
    0/B 00/U    00/U    00/U    22/W    10/U    11/U
4BQ 072 042/072 042/075 045/076 045/064 039/070 041/069
    0/B 00/U    00/U    00/U    11/B    10/U    00/U
BHK 066 040/068 039/071 042/073 043/063 038/067 040/066
    0/B 00/U    00/U    00/U    12/W    10/U    00/U
SHR 073 039/072 039/078 042/078 041/066 036/071 038/070
    2/T 00/U    00/U    00/U    21/B    00/U    00/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

&&

$$
WEATHER.GOV/BILLINGS


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