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 021706
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
919 AM MDT THU JUL 2 2015

.DISCUSSION...

TODAY...UPDATE TO ZONES NOT PLANNED...THE REGION REMAINS UNDERNEATH
HIGH PRESSURE ALOFT BUT SOME INSTABILITY WILL DEVELOP THIS
AFTERNOON. A WEAK DISTURBANCE ALOFT WILL MOVE THROUGH THE AREA AND
SOME ISOLATED THUNDERSTORM ACTIVITY IS EXPECTED. MOST CONVECTION
WILL BE RESTRICTED TO HIGHER ELEVATIONS.  CURRENT FORECAST LOOKS ON
TRACK. ZELZER

&&

.AVIATION

UPDATED 1705Z.

HIGH PRESSURE WILL CONTINUE OVER CENTRAL AND SOUTHWEST MONTANA. THE
AIRMASS WILL REMAIN QUITE DRY BUT BECOME SLIGHTLY UNSTABLE DURING
THE AFTERNOON. ISOLATED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE...MAINLY OVER HIGHER ELEVATION IN CENTRAL AND NORTHERN
PORTIONS OF THE AREA. CONDITIONS HAVE IMPROVED BUT MOUNTAINS COULD
BE OBSCURED DUE TO SMOKE. ELSEWHERE, VFR CONDITIONS WILL PREVAIL
THROUGH THE NEXT 24 HOURS.

&&

.PREV DISCUSSION...
/ISSUED 522 AM MDT THU JUL 2 2015/

TODAY THROUGH SATURDAY NIGHT...AREA REMAINS BENEATH A RELATIVELY DRY
AND WARM WEST-NORTHWEST FLOW ALOFT TODAY WHILE AT THE SURFACE, HIGH
PRESSURE EXTENDING FROM AB SOUTH INTO MT WILL MAINTAIN RELATIVELY
LIGHT WINDS WITH TEMPERATURES ABOUT 5-10 DEGREES ABOVE SEASONAL
AVERAGES. A NARROW BAND OF MID LEVEL MOISTURE/CLOUD-COVER EVIDENT
ON SATELLITE IMAGERY THIS MORNING FROM NW-SE ACROSS NORTH CENTRAL
MT, AS WELL AS A WEAK EMBEDDED SHORTWAVE FEATURE, CURRENTLY IN THE
VICINITY OF VANCOUVER ISLAND MAY PROVIDE ENOUGH MOISTURE/LIFT FOR AN
ISOLATED WEAK THUNDERSTORM ALONG THE ROCKY MTN FRONT AND CENTRAL MT
MTNS THIS AFTERNOON/EVENING. OTHERWISE DRY CONDITIONS WILL PREVAIL.
WARMER AND CONTINUED DRY CONDITIONS ARE EXPECTED FRIDAY AS THE
THERMAL TROUGH OVER THE GREAT BASIN AND INTERIOR PACIFIC NW SHIFTS
EAST ACROSS THE ROCKIES.

A RELATIVELY VIGOROUS UPPER LEVEL LOW CURRENTLY MOVING INTO THE
AK PANHANDLE WILL MOVE INTO NORTHERN AB/SK SATURDAY WITH A
MODERATELY STRONG CANADIAN COLD FRONT PUSHING SOUTH ACROSS NORTH
CENTRAL MT LATE SATURDAY AFTERNOON AND EVENING. THIS, IN
COMBINATION WITH SHORTWAVE AND UPPER LEVEL JET ENERGY ASSOCIATED
WITH THE CANADIAN TROUGH WILL BRING A CHANCE FOR SHOWERS AND
THUNDERSTORMS TO NORTHERN PORTIONS OF THE FORECAST AREA SATURDAY
AFTERNOON AND CENTRAL PORTIONS OF THE FORECAST AREA SATURDAY
NIGHT. TIMING OF THE FRONTAL BOUNDARY IS STILL SOMEWHAT
QUESTIONABLE WITH VARYING SOLUTIONS BUT THE COMBINATION OF
CONVECTION AND A SIGNIFICANT WIND SHIFT AND PERIOD OF GUSTY WINDS
FOLLOWING THE FRONTAL PASSAGE COULD IMPACT SOME INDEPENDENCE DAY
EVENING EVENTS ACROSS PORTIONS OF NORTH CENTRAL MT. HOENISCH

SUNDAY THROUGH THURSDAY...A REX BLOCK PATTERN TO BE ESTABLISHED
SATURDAY OVER THE EASTERN PACIFIC IS MAINTAINED THROUGH EARLY
TUESDAY. THIS SUPPORTS A WEAKLY CONFLUENT WESTERLY FLOW ACROSS
MONTANA SUNDAY. NORTHERLY WINDS ASSOCIATED WITH STRENGTHENING
SURFACE HIGH PRESSURE WILL PROVIDE REFRESHING TEMPERATURES NEAR TO
SLIGHTLY BELOW AVERAGE. SCATTERED MOUNTAIN SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE SUNDAY AFTERNOON ALONG A STALLED FRONTAL BOUNDARY
WHERE THE ENVIRONMENT REMAINS WARMER AND SLIGHTLY UNSTABLE. SUNNY
AND WARMER CONDITIONS SETTLE IN FOR MONDAY.

A STRONGER SHORTWAVE TROUGH DEPICTED CONSISTENTLY IN MODEL GUIDANCE
DROPS SOUTHWARD THROUGH WESTERN CANADA LATE TUESDAY AS THE PACIFIC
RIDGE DECAYS. THIS WILL PRODUCE WIDELY SCATTERED THUNDERSTORMS
TUESDAY AFTERNOON. SHOWERS CONTINUE TUESDAY NIGHT WITH ADDITIONAL
THUNDERSTORMS WEDNESDAY. SOME THESE STORMS MAY PRODUCE HEAVY
RAINFALL AS SOUTHWEST MOISTURE IS DRAWN INTO THE MIX. TEMPERATURES
TREND DOWN TO NEAR AVERAGE ON TUESDAY AND WEDNESDAY. ENSEMBLE
FORECASTS SUGGEST UNCERTAINTY REGARDING THE POSITION OF THE CLOSED
LOW OFF THE CALIFORNIA COAST. THE POSITION OF THIS SYSTEM WILL
INFLUENCE MID LAYER STABILITY AND MOISTURE AVAILABILITY FOR
THUNDERSTORM ACTIVITY. NUTTER

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  84  57  91  59 /  10  10  10  10
CTB  82  53  89  55 /  10  10  10  10
HLN  90  61  95  62 /  10  10  10  10
BZN  87  52  91  52 /   0   0  10  10
WEY  80  42  82  42 /   0   0  10  10
DLN  88  54  90  53 /   0   0  10   0
HVR  86  56  94  59 /  10   0   0  10
LWT  82  56  89  59 /  10  10  10  10

&&

.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.