Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 281010
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
410 AM MDT TUE JUL 28 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
STACKED LOW PRESSURE SYSTEM MOVING ACROSS NORTHEAST MONTANA THIS
MORNING WITH RAIN WRAPPING BACK INTO NORTH CENTRAL MONTANA BEHIND
THE SYSTEM. THIS RAIN IS EXPECTED TO CONTINUE TO SPREAD EAST
THROUGH THE DAY AS THE LOW LIFTS TOWARD SOUTHERN MANITOBA.
HEAVIEST RAIN IS ANTICIPATED ALONG THE CANADIAN BORDER WHERE A
TROWAL FEATURE IS DEVELOPING AS THE UPPER LOW CLOSES OFF. WITH
AN ADDITIONAL 1 TO 2 INCHES OF RAIN...AND POSSIBLY LOCALIZED
HIGHER AMOUNTS IF CONVECTION DEVELOPS...OVER ALREADY SATURATED
GROUND...THE THREAT FOR AREAL FLOODING CONTINUES TODAY.

WITH COLD AIR ADVECTION ALONG WITH THE TIGHT PRESSURE GRADIENT AS
THE LOW WINDS UP...WITH SEE THE DEVELOPMENT OF VERY STRONG WINDS
BY LATE MORNING. MODELS CONTINUE TO DEPICT 50 TO 70 KNOT 850MB
WINDS MOVING ACROSS NORTHEAST MONTANA FROM LATE MORNING INTO THE
AFTERNOON. RAIN HAS THE POTENTIAL TO DAMPEN OUT THESE WINDS FROM
BEING REALIZED AT THE SURFACE...BUT COULD ALSO PROVIDE SOME
DOWNWARD ACCELERATION. HOWEVER GIVEN THE STRONG SPEEDS IN THE MODELS
EXPECTED HIGH WINDS ACROSS MUCH OF THE CWA...AND WILL CONTINUE THE
HIGH WIND WARNING.

COOL TEMPERATURES EXPECTED TODAY WITH THE CLOUDS AND RAIN
SUPPRESSING HEATING AS WELL THE COLDER AIR WRAPPING IN BEHIND THE
LOW. WINDS AND RAIN WILL TAPER OFF DURING THE EVENING HOURS AS THE
LOW REACHES MANITOBA WITH CLEARING EXPECTED LATE TONIGHT. EBERT

WEDNESDAY THROUGH THURSDAY... HOT HIGH PRESSURE FROM DOWN SOUTH
WILL REBOUND ACROSS THE AREA AS COOL SURFACE AIR SHALLOWS OUT
WEDNESDAY. FLOW ALOFT WILL BECOME ZONAL TO SLIGHTLY NORTHWEST
AND THE ATMOSPHERE SHOULD BE STABLE WITH MOSTLY CLEAR SKIES AND
DRY CONDITIONS. GAH


.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...

SYNOPTIC SET UP...A LARGE TROUGH RUNS THROUGH NUNAVUT NORTHERN
MANITOBA AND INTO ONTARIO. A LARGE HOT HIGH PRESSURE RIDGE HAS
DEVELOPED OVER THE WESTERN THIRD OF THE CONUS. NORTHEAST MONTANA
WILL BE WEDGED BETWEEN THESE TWO FEATURES IN SEMI ZONAL TO
NORTHWESTERN FLOW. FARTHER NORTHWEST A LARGE TROUGH SETS OVER THE
GULF OF ALASKA WHICH COULD LET A SHORTWAVE OR TOW FLY OVER THE
ROCKIES INTO HIGH PLAINS.

THURSDAY NIGHT THROUGH FRIDAY NIGHT.... MODELS ARE IN GOOD
AGREEMENT WITH MOSTLY CLEAR SKIES AND DRY... WARM CONDITIONS.

SATURDAY TO MONDAY... WEAK SHORTWAVES INT EH FLOW WILL EXIT THE
SOUTHERN ALBERTAN FRONT RANGE. TIMING IS UNKNOWN FOR EACH OF THESE
PASSAGES AND THEY QUICKLY KNOCK THE MODELS OUT OF FULL ALIGNMENT
DUE TO THEIR SUBTLY. POPS RISE BACK UP BUT DO NOT QUITE HIT
MENTION YET... DUE TO MOST OF THE ENERGY STAYING NORTH OF THE BORDER.
CONFIDENCE IS AVERAGE DURING THESE PERIODS.

MONDAY NIGHT ONWARD... GULF OF ALASKA TROUGH BREAKS APART AND
TRAVELS ACROSS THE ROCKIES EXITING THE CANADIAN FRONT RANGE. THE
IMPACT HERE IS IN QUESTION DEPENDING ON MODEL. THE GFS FAVORS A
RIDGE ACROSS THE CWA WHICH BLOCKS THE MOVEMENT OF THIS TROUGH AND
ITS ENERGY INTO THE AREA. THE EC FAVORS THE TROUGH COMING ACROSS
AND DROPPING SOUTH INTO THE CWA. CONFIDENCE IS BELOW AVERAGE HERE
AND HAD TO SPLIT THE DIFFERENCE ON TEMPERATURES UNTIL SOME FORM OF
ALIGNMENT OCCURS. GAH

&&

.AVIATION...
FLIGHT CATEGORY: MVFR WITH FUEL LOADING MAINLY DUE TO LOW
CLOUDS... IMPROVING TO VFR NEAR THE END OF THE CYCLE. ISOLATED IFR
POSSIBLE.

SYNOPSIS: A POWERFUL STORM SYSTEM IS MOVING ACROSS THE NORTHEAST
MONTANA AND WILL BRING RAIN... LOW CLOUDS... AND VERY STRONG
WINDS THROUGH TUESDAY. WIDESPREAD RAIN WILL EXIT TUESDAY EVENING.

AREA WINDS: WEST AT 20 TO 30 KTS GUSTING TO 40 THIS MORNING...
INCREASING TO 30 TO 40 KTS GUSTING 50 KTS AFTER SUN-UP... CALMING WILL
BEGIN DURING THE EVENING HOURS.

GAH


&&

.HYDROLOGY...
WATER RISES ARE ALREADY BEGINNING ALONG BEAVER CREEK NEAR SACO AND
HINSDALE AS WELL AS ON THE VARIOUS BRANCHES OF THE POPLAR RIVER
NEAR THE CANADIAN BORDER DUE TO EXCESSIVE RAIN FALL ON MONDAY.

WITH AN ADDITIONAL 1 TO 2 INCHES OF RAIN EXPECTED ACROSS THE
REGION NORTH OF THE MISSOURI RIVER TODAY...RIVER RISES ARE
ANTICIPATED THROUGH THE WEEK ALONG BEAVER CREEK...AND THE MILK AND
POPLAR RIVERS. MANY OTHER STREAMS AND CREEKS ACROSS THE REGION
WILL ALSO SEE HIGH WATER. EBERT

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 9 AM THIS MORNING TO 9 PM MDT THIS
EVENING FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND
SOUTHERN VALLEY...DANIELS...DAWSON...EASTERN ROOSEVELT...
GARFIELD...MCCONE...NORTHERN PHILLIPS...NORTHERN VALLEY...
PETROLEUM...PRAIRIE...RICHLAND...SHERIDAN...SOUTHWEST PHILLIPS...
WESTERN ROOSEVELT...WIBAUX.

FLOOD WATCH THROUGH THIS AFTERNOON FOR CENTRAL AND SOUTHEAST
PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...NORTHERN
PHILLIPS...NORTHERN VALLEY...SOUTHWEST PHILLIPS...WESTERN
ROOSEVELT.

LAKE WIND ADVISORY UNTIL 9 AM MDT THIS MORNING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





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