Area Forecast Discussion
Issued by NWS Great Falls, 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 KTFX 022146
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
346 PM MDT SUN AUG 2 2015

.DISCUSSION...

TONIGHT THROUGH TUESDAY...HIGH PRESSURE ALOFT WILL KEEP NORTH
CENTRAL AND SOUTHWEST MONTANA MOSTLY CLEAR OVERNIGHT AND INTO THE
DAY ON MONDAY, BUT THIN LAYERS OF SMOKE ALOFT FROM WILDFIRES
ACROSS THE PACIFIC NORTHWEST WILL REMAIN OVER MUCH OF THE AREA. A
DISTURBANCE CURRENTLY OVER THE SOUTHWESTERN U.S. WILL THEN MOVE
NORTHEAST OVER THE GREAT BASIN ON MONDAY AND EVENTUALLY THROUGH
THE FORECAST AREA MONDAY NIGHT INTO TUESDAY. THIS WILL BRING AN
INCREASING CHANCE OF SHOWERS AND A MIX OF WET AND DRY
THUNDERSTORMS TO THE AREA FROM THE SOUTHWEST, ESPECIALLY MONDAY
NIGHT INTO TUESDAY. GUSTY ERRATIC WIND GUSTS WILL BE THE MAIN
THREAT FROM THESE STORMS, BUT VERY SMALL HAIL CANNOT BE RULED OUT.
TEMPERATURES AHEAD OF THIS DISTURBANCE WILL WARM TO BETWEEN 5 AND
10 DEGREES ABOVE NORMAL FOR MOST OF THE AREA ON MONDAY. HOWEVER,
A PACIFIC COLD FRONT ASSOCIATED WITH THE DISTURBANCE WILL MOVE
THROUGH THE AREA LATE MONDAY NIGHT AND THROUGH THE DAY ON TUESDAY,
WHICH WILL COOL TEMPERATURES TO BETWEEN 5 AND 10 DEGREES BELOW
NORMAL FOR TUESDAY. BREEZY SOUTHEAST WINDS AHEAD OF THIS SYSTEM
WILL ALSO SHIFT MORE WESTERLY BEHIND THE FRONT ON TUESDAY. GUSTS
COULD POTENTIALLY EXCEED 40 MPH AT TIMES ALONG THE ROCKY MOUNTAIN
FRONT, ESPECIALLY WITH THE FRONTAL PASSAGE TUESDAY MORNING. THIS
SITUATION WILL NEED TO BE MONITORED CLOSELY WITH ONGOING FIRE
FIGHTING EFFORTS ON THE REYNOLDS CREEK FIRE IN THE EASTERN PORTION
OF GLACIER NATIONAL PARK.  COULSTON

TUESDAY NIGHT THROUGH SUNDAY...THE EXTENDED PERIOD WILL BE
CHARACTERIZED BY AN UNSETTLED ZONAL FLOW. TEMPERATURES WILL
REMAIN NEAR TO JUST BELOW AVERAGE. A SHORTWAVE FEATURE WILL
GENERATE SHOWERS OVER THE SOUTHWEST ON WEDNESDAY. MODELS SUGGEST
THE REST OF THE PERIOD WILL BE MAINLY DRY...BUT WILL CONTINUE TO
CARRY SLIGHT CHANCES FOR PRECIP GIVEN LOWER MODEL CONFIDENCE AMID
THE DISTURBED AND MOIST FLOW. PN

&&

.AVIATION...
UPDATED 1740Z.

HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE DRY AND
STABLE CONDITIONS. SURFACE WINDS WILL GENERALLY BE 10 TO 12 KTS
OR LESS. VFR CONDITIONS PREVAIL.

&&

.FIRE WEATHER...
WARMING TEMPERATURES ACROSS THE FIRE DISTRICTS ON MONDAY WITH
RELATIVE HUMIDITIES FALLING MOSTLY INTO THE 15 TO 25 PERCENT RANGE
WILL COMBINE WITH 10 TO 20 MPH SOUTHEAST WINDS OVER THE PLAINS TO
INCREASE FIRE CONCERNS. HOWEVER, THESE WIND AND HUMIDITY VALUES
ARE ONLY MARGINAL FOR FIRE WEATHER HIGHLIGHTS, SO WILL HOLD OFF ON
ANY FOR NOW. A DISTURBANCE MOVING INTO THE AREA FOR MONDAY
AFTERNOON THROUGH TUESDAY WILL THEN BRING A INCREASING CHANCE OF
WET AND DRY THUNDERSTORMS. AFTER THIS RECENT WARM AND DRY PERIOD,
LIGHTNING STRIKES MAY INCREASE THE POTENTIAL FOR NEW FIRE STARTS.
HOWEVER, AS THE DISTURBANCE MOVES INTO THE AREA, COOLER
TEMPERATURES AND IMPROVED RELATIVE HUMIDITY WILL HELP MITIGATE
FIRE CONCERNS. ALSO, IN THE WAKE OF THE DISTURBANCE, THE BREEZY
WINDS WILL SHIFT MORE WESTERLY, BUT AGAIN HUMIDITIES WILL
GENERALLY BE IMPROVING BY THIS TIME.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  58  94  63  80 /   0  10  20  40
CTB  55  94  61  79 /   0  10  20  40
HLN  56  96  60  82 /   0  10  30  40
BZN  53  90  56  80 /   0  20  30  40
WEY  39  79  44  72 /   0  30  40  40
DLN  53  86  55  79 /   0  30  40  40
HVR  56  92  60  84 /   0   0  20  50
LWT  55  90  58  78 /   0  10  20  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS


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