Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 021122
AFDTFX

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

UPDATED AVIATION DISCUSSION

.DISCUSSION...

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


&&

.AVIATION
UPDATED 1122Z.

VFR CONDITIONS PREVAIL THROUGH THE PERIOD WITH THE REGION REMAINING
UNDER A RELATIVELY DRY WNW FLOW ALOFT WITH SURFACE WINDS GENERALLY
LIGHT. CUMULUS DEVELOPMENT OVER THE MTNS THIS AFTERNOON MAY RESULT
IN AN ISOLATED THUNDERSTORM ALONG THE ROCKY MTN FRONT AND LITTLE
BELT MTNS, OTHERWISE SKIES WILL BE CLEAR TO PARTLY CLOUDY. HOENISCH

&&

.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


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