Area Forecast Discussion
Issued by NWS Glasgow, 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 KGGW 010235
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
835 PM MDT FRI JUL 31 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...

UPDATE...HIGH PRESSURE CONTINUES OVER THE REGION KEEPING THE
WEATHER QUIET. NO CHANGES TO THE ON GOING FORECAST TONIGHT AS ALL
REMAINS IN LINE WITH THE CURRENT THINKING.       PROTON

PREVIOUS DISCUSSION...
A RIDGE OF HIGH PRESSURE OVER THE WESTERN STATES WILL CONTINUE TO
BRING WARM/HOT CONDITIONS DURING THIS PERIOD. BUT AN UPPER LOW
OVER CENTRAL AND EASTERN CANADA HAS SHOWN A BIT MORE MUSCLE AND
WILL PUSH SOME OF THE HOT AIRMASS TO OUR SOUTH THIS WEEKEND.

A WEAK SURFACE LOW OVER SOUTHERN ALBERTA WILL DRIFT SOUTHEAST AND
CROSS NE MT EARLY ON THE FIRST DAY OF AUGUST. WEST/NORTHWEST WINDS
WILL INCREASE AS A RESULT AND SHOULD HELP TO WARM THE AREA INTO
90S MOST PLACES AS 850 MB TEMPS WARM TO ABOUT 23-27*C. MIN
HUMIDITY DROPPING TO NEAR 10% IN THE SOUTHWEST ZONES WOULD
NORMALLY LEAD TO FIRE WEATHER CONCERNS BUT SINCE THE AREA RECEIVED
ABOUT .5" OF RAIN EARLY THIS WEEK...WILL LEAVE IT MENTIONED IN THE
FIRE WEATHER DISCUSSION FOR NOW.

AS THE SURFACE LOW MOVES FURTHER AWAY SATURDAY NIGHT...COOLER AIR
FROM CANADA WILL FILTER IN. HIGH TEMPERATURES SUNDAY ARE EXPECTED TO
BE UP TO 8 DEGREES COOLER THAN SATURDAY. TFJ


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

SYNOPTIC SET UP... LONG RANGE BEGINS WITH A RIDGE OVER THE WESTERN
HALF OF THE CONUS AND A TROUGH OVER THE CANADIAN SHIELD.
NORTHEAST MONTANA LIES BETWEEN THESE TWO LARGE FEATURES UNDER
NORTHWEST FLOW ALOFT. FARTHER WEST A CLOSED LOW SETS OVER THE
COAST OF BRITISH COLUMBIA.

SUNDAY THOUGH MONDAY... RIDGE TO THE WEST AND LACK OF MOISTURE
SOURCE SHOULD KEEP NEMONT WARM AND DRY THROUGH THESE PERIODS.
MEANWHILE THE BRITISH COLUMBIA LOW WILL DIG SOUTH TO THE PACIFIC
NORTHWEST. CONFIDENCE IS HIGH.

MONDAY NIGHT THROUGH THURSDAY... CREST OF THE RIDGE WILL BE MOVED
NORTH INTO THE HIGH PLAINS BY THE DIGGING CLOSED LOW TO THE WEST. AS
THE WESTERN SIDE OF THE RIDGE AXIS OVERTAKES THE AREA... PACIFIC
MOISTURE WILL BEGIN TO TRUCK IN FROM TOFF THE COAST OF NORTHERN
CALIFORNIA AND THE PACIFIC NORTHWEST. INSTABILITY WILL FINALLY
DEVELOP ALLOWING FOR A RETURN TO SHOWERS THUNDERSTORMS. RIDGE IN
PLACE IS NORMALLY ABOVE AVERAGE CONFIDENCE BUT RMOP PREDICTABILITY
SEEMS LOW. MEANWHILE SUBTLE WAVES INT EH SYNOPTIC PATTERN SEEM TO
BE GIVING THE ENSEMBLE STANDARD DEVIATION PRODUCT GRIEF SO
CONFIDENCE HAS BE BACK DOWN TO AVERAGE.

THURSDAY NIGHT ONWARD... TOP OF THE RIDGE EXITS AND MODELS ARE
UNSURE HOW SHARPLY THE TROUGH THE THE WEST WILL MANEUVER.
CONFIDENCE IN THESE PERIODS IS AVERAGE TO SLIGHTLY BELOW. GAH

PREVIOUS LONG TERM DISCUSSION...
UPPER RIDGE WILL BE OVER THE AREA WITH DRY WEATHER SUNDAY NIGHT
INTO MONDAY MORNING. THE SHORTWAVE TROUGH WILL FLATTEN THE RIDGE
SOMEWHAT ON TUESDAY. THIS WAVE WOULD INTERACT WITH A QUASI-
STATIONARY FRONT TO BRING A CHANCE OF THUNDERSTORMS STARTING
MONDAY AFTERNOON AND LASTING THROUGH TUESDAY.

THE RIDGE REBOUNDS SOMEWHAT ON WEDNESDAY BUT THE QUASI-STATIONARY
FRONT REMAINS OVER THE AREA AND ANOTHER SHORTWAVE TROUGH MOVES
ACROSS THE RIDGE BRINGING ANOTHER CHANCE OF THUNDERSTORMS.

MORE WAVES ARE EXPECTED ACROSS THE RIDGE THURSDAY AND FRIDAY AS
QUASI-STATIONARY FRONT REMAINS IN PLACE. WILL CONTINUE A CHANCE OF
SHOWERS AND THUNDERSTORMS. FORRESTER

&&

.AVIATION...
EXPECT VFR FLIGHT CONDITIONS OVERNIGHT WITH LIGHT AND VARIABLE
WINDS. MALIAWCO


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW





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