Flash Flood Warning 1, NWS Glasgow, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
903 AM MST MON FEB 14 2011

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
MADE SOME TWEAKS TO LOWER TEMPS IN SOUTH-CENTRAL VALLEY COUNTY. REST
OF FORECAST LOOKED GOOD. JAMBA

PREVIOUS DISCUSSION...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWS AN UPPER LEVEL
RIDGE OVER THE WESTERN CONUS REBUILDING OVER THE ROCKY MOUNTAINS
WHILE AN UPPER LEVEL TROUGH DIGS EASTWARD THROUGH THE GREAT LAKES
REGION. A TIGHTLY WOUND UPPER TROUGH IS APPROACHING THE WEST COAST
AS PLENTIFUL MOISTURE STREAMS AHEAD OF IT ACROSS MOST OF THE
NORTHWESTERN CONUS.

FORECAST CHALLENGES WILL FOCUS MAINLY ON TEMPERATURES AS THE SHORT
TERM FORECAST IS QUIET AND GENERALLY CALM. RISING CREEKS AND
STREAMS WILL ALSO BE OF CONCERN AS THE SNOW PACT IS EXPECTED TO
CONTINUE TO MELT THROUGHOUT THE SHORT TERM FORECAST PERIOD.

PARTLY CLOUDY SKIES...WINDS AROUND 10 KTS...AND CONTINUED WARMING
DAYTIME TEMPERATURES SEEM TO PAINT THE SHORT TERM FORECAST
PICTURE.

EVEN THOUGH MODEL DATA CONTINUES TO HINT AT WIDESPREAD FOG FOR THE
MORNING HOURS OVER THE NEXT SEVERAL DAYS...A PARTIAL CLOUD COVER
WILL TEND TO INHIBIT FOG DEVELOPMENT. I KEPT FOG OUT OF THE
FORECAST...BUT IF SKIES CLEAR DURING THE OVERNIGHT AND EARLY
MORNING HOURS FOR MORE THAN JUST A COUPLE OF HOURS...FOG
DEVELOPMENT POTENTIAL IS THERE AND IS WORTH KEEPING A EYE ON.

DAILY SATELLITE IMAGERY WILL BEGIN TO REVEAL THE MELTING AND
RETREATING EDGE TO THE SNOW FIELD WHICH IS ALREADY EVIDENT IN
PHILLIPS AND PETROLEUM COUNTIES. BEST CHANCE FOR CLEAREST SKIES
WILL LIKELY BE TODAY.

THE TIGHT WEST COAST UPPER TROUGH IS JUST A WEAK PRECURSOR...A
DISAPPEARING SAMPLING OF THE LARGE WEST COAST UPPER TROUGH SET TO
BRING THE WESTERN CONUS INTO A PROLONGED PERIOD OF STORMINESS
BEGINNING TODAY AND CONTINUING OVER THE NEXT SEVERAL DAYS. MOST
OF THAT PRECIPITATION IS WRUNG OUT OVER THE MOUNTAINS BEFORE IT
HAS A CHANCE TO MAKE IT THIS FAR EAST TO NE MONTANA...KEEPING THE
SHORT TERM FORECAST DRY.

AS THE UPPER TROUGH TAKES OVER MORE OF THE WESTERN
CONUS...PRECIPITATION WILL BEGIN TO NOSE INTO THE WESTERN PORTIONS
OF OUR CWA BY WEDNESDAY AS A RAIN AND SNOW MIX. BMICKELSON

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
PATTERN SHIFT IN STORE FOR THE END OF THE WEEK AS UPPER TROF
DROPS OUT OF THE GULF OF ALASKA TO REPLACE RIDGE OVER THE
INTERMOUNTAIN WEST AND EAST PACIFIC RIDGE THAT HAS DOMINATED THIS
WINTER REBUILDS. RECENT VERY WARM TEMPERATURES WILL GIVE WAY TO
WHAT HAS BEEN MORE TYPICAL OF THIS WINTER...COLD AND SNOWY
WEATHER.

ARCTIC FRONT DROPPING INTO MONTANA ON WEDNESDAY WITH PACIFIC
SHORTWAVE PUSHING MOISTURE ACROSS IT WEDNESDAY NIGHT AND THURSDAY.
MODELS A BIT FASTER WITH BOTH THE COLD AIR SINKING SOUTHWARD AND
THE WAVE MOVING ALONG THE FRONT...ESPECIALLY THE 0Z GFS. THE 06Z
GFS MOVED THE BAND BACK TO THE NORTH...MORE IN LINE WITH THE ECMWF
AND PREVIOUS MODEL RUNS. KEPT WITH CONSISTENCY OF POSITION BUT
SPED UP THE TIMING SLIGHTLY AS THE BAND MOVES EAST. LESS AGREEMENT
ON SNOW AMOUNTS...PARTICULARLY GIVEN THE SHIFT OF POSITION AND
TIMING OF COLD AIR INTRUSION...BUT STILL EXPECT AT LEAST TWO
INCHES OF SNOW ACROSS PART OF THE FORECAST AREA WEDNESDAY NIGHT
INTO THURSDAY.

COLD AIR ADVECTION AT THE BEGINNING OF THE EXTENDED PERIOD WILL
ALSO LIKELY LEAD TO FALLING OR AT LEAST STEADY TEMPERATURES ON
THURSDAY AND BLOWING SNOW AS WINDS INCREASE FROM THE NORTHWEST.
COLD AIR LINGERS ON FRIDAY AS HIGH PRESSURE SLIDES INTO EASTERN
MONTANA.

MUCH GREATER UNCERTAINTY FOR THE FORECAST BEYOND FRIDAY AS MODELS
DIFFERING ON HOW STUBBORN THE ARCTIC AIRMASS WILL BE TO MOVE.
ECMWF HOLDS ON TO THE COLD...AND BRINGS REINFORCING SHOTS OF COLD
AIR WITH A SERIES OF WAVES MOVING THROUGH THE UPPER FLOW. GFS HAS
SIMILAR SHORTWAVES...BUT PULLS WARM AIR BACK NORTH AHEAD OF THEM.
EBERT

&&

.AVIATION...
VFR CONDITIONS WITH MID TO HIGH CLOUDS EXPECTED TODAY. WINDS WILL
MUCH LIGHTER TODAY AND FROM THE SOUTH TO SOUTHEAST. RAE

&&

.HYDROLOGY...
WITH RECENT WARM TEMPERATURES THE POSSIBILITY FOR FLOODING ON
AREA STREAMS AND CREEKS WILL CONTINUE THROUGH MIDWEEK...
ESPECIALLY SOUTH AND WEST OF A WHITEWATER- GLASGOW- GLENDIVE LINE.
FLATWILLOW CREEK IN PETROLEUM COUNTY IS REPORTED TO BE OUT OF ITS
BANKS AND THE MUSSELSHELL RIVER IS EXPECTED TO PEAK AROUND 13
FEET OR 5 FEET ABOVE FLOOD STAGE THIS MORNING. A FLOOD ADVISORY
IS IN EFFECT FOR MOST OF PETROLEUM COUNTY INCLUDING THE
MUSSELSHELL RIVER.

&&

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

&&

WEATHER.GOV/GLASGOW

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GLASGOW MT
313 AM MST MON FEB 14 2011

MTZ021-022-151100-
PETROLEUM-GARFIELD-
313 AM MST MON FEB 14 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
MONTANA.

.DAY ONE...TODAY AND TONIGHT

A FLOOD ADVISORY DUE TO SNOW MELT IS IN EFFECT UNTIL NOON FOR THE
MUSSELSHELL RIVER AND UPSTREAM TRIBUTARY CREEKS IN PETROLEUM
COUNTY. MUDDY ROADS...AND WATER PONDING AND FLOWING OVER LOW LYING
ROADS WILL MAKE TRAVEL DIFFICULT AND HAZARDOUS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

ANOTHER STORM SYSTEM WILL BRING COLDER TEMPERATURES AND CHANCES OF
SNOW TO THE AREA LATER THIS WEEK. SOME SNOW ACCUMULATION CAN BE
EXPECTED.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

MTZ016>020-023>027-059>062-151100-
CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-
DANIELS-SHERIDAN-WESTERN ROOSEVELT-MCCONE-RICHLAND-DAWSON-PRAIRIE-
WIBAUX-NORTHERN PHILLIPS-SOUTHWEST PHILLIPS-NORTHERN VALLEY-
EASTERN ROOSEVELT-
313 AM MST MON FEB 14 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
MONTANA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

ANOTHER STORM SYSTEM WILL BRING COLDER TEMPERATURES AND CHANCES OF
SNOW TO THE AREA LATER THIS WEEK. SOME SNOW ACCUMULATION CAN BE
EXPECTED.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.