Special Weather Statement, NWS Great Falls, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
227 PM MDT SUN AUG 9 2009

.DISCUSSION...

TONIGHT THROUGH TUESDAY...AIRMASS WILL REMAIN MARGINALLY UNSTABLE
THROUGH THIS EVENING WITH ISOLATED CONVECTION MAINLY CONFINED TO THE
MOUNTAINS. BREEZY AFTERNOON WINDS ARE EXPECTED TO DIMINISH FAIRLY
RAPIDLY DURING THE EVENING HOURS AS WELL. THE WORK WEEK STARTS OFF
WITH A WEAK...BROAD RIDGE OVER THE NORTHERN PLAINS AND WEST TO
SOUTHWEST FLOW ALOFT OVER MONTANA. THE AIRMASS WILL BE GENERALLY DRY
FROM LATE TONIGHT THROUGH TUESDAY MORNING WITH A WARMING TREND
EXPECTED. HAVE AGREED WITH SURROUNDING OFFICES TO ADD A SLIGHT
CHANCE OF THUNDERSTORMS TO THE MOUNTAINS NEAR YELLOWSTONE PARK
MONDAY AFTERNOON AND EVENING. MAIN WEATHER CONCERN DURING THIS TIME
FRAME WILL BE BREEZY WINDS OVER PORTIONS OF NORTH CENTRAL MONTANA
DURING THE AFTERNOON AND EVENING HOURS MONDAY AND TUESDAY WHICH WILL
BEAR WATCHING FOR FIRE WEATHER CONCERNS.

TUESDAY NIGHT THROUGH FRIDAY NIGHT...WINDY CONDITIONS ALONG WITH
NEAR SEASONAL NORMAL TEMPERATURES WILL CONTINUE WITH BOTH MODELS IN
GOOD AGREEMENT OVER THE GENERAL SYNOPTIC PATTERN FOR MOST OF THE
LONG TERM. EXACT TIMING OF A COUPLE OF UPPER LEVEL DISTURBANCE THAT
WILL MOVE MAINLY NORTH OF THE AREA APPEARS TO BE THE ONLY POINT OF
CONTENTION BEFORE FRIDAY. THE MODELS HAVE COME INTO BETTER AGREEMENT
ABOUT THE POSSIBILITY OF A HIGH AMPLITUDE TROUGH DIGGING DOWN ACROSS
THE CANADIAN COAST AND INTO THE NORTHWEST BY FRIDAY. WHILE THE
EUROPEAN KEEPS THE LOW CLOSED...BOTH THE EUROPEAN AND THE GFS HAVE
THE SIMILAR TIMING...BUT GFS IS MOVING A LARGER AMOUNT OF ENERGY
SOUTHWARD INTO THE STATES. THIS SOLUTION COULD CAUSE SOME SEVERE
STORM POSSIBILITIES LATER AND THE WEEK ALONG WITH ANOTHER DECENT
SHOT OF PRECIPITATION. RIGHT NOW HAVE LEFT POPS AND QPF LOW DUE TO
THE LACK OF CONFIDENCE WITH THIS SOLUTION. FIRE WEATHER CONCERNS ARE
STILL POSSIBLE IN THE MIDDLE OF THE WEEK HOWEVER FUEL CONDITIONS MAY
BE THE LIMITING FACTOR ON ANY SORT OF FIRE WEATHER PRODUCT. SUK

SATURDAY AND SUNDAY...ENSEMBLES SHOW AN UPPER LEVEL RIDGE OVER THE
INTER-MOUNTAIN WEST WITH AN UPPER LEVEL TROUGH OVER THE WEST COAST.
HOWEVER...BOTH ECMWF AND GFS MODELS INDICATE A SHORT WAVE TROUGH
MOVING THROUGH MONTANA DURING THE PERIOD. THUS...WILL GO WITH THE
AVERAGE OF THE MODELS. SO WILL GO WITH NEAR SEASONAL TEMPERATURES
AND A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS DURING THE
AFTERNOON AND EVENING HOURS...ESPECIALLY OVER THE MOUNTAINS.
WILLIAMSON DC

&&

.AVIATION...
UPDATED 1810Z.
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES FOR THE NEXT 24 HOURS.
DRIER CONDITIONS ARE EXPECTED ACROSS MOST AREAS WITH THE EXCEPTION
OF AN ISOLATED SHOWER OR THUNDERSTORM ACROSS SOUTHWEST MONTANA. A CB
OR TWO MAY DEVELOP NEAR HIGHER TERRAIN...NOT ANTICIPATING ANY STORMS
OR SHOWERS DIRECTLY AFFECTING TAF SITES TODAY THOUGH. WINDS WILL BE
GENERALLY WESTERLY IN NATURE WITH SOME GUSTS INTO THE TEENS POSSIBLE
DURING THE AFTERNOON ACROSS THE PLAINS.

&&

.FIRE WEATHER...WARM TEMPERATURES AND GOOD MIXING WILL CAUSE BREEZY
TO WINDY CONDITIONS ACROSS PORTIONS OF NORTH CENTRAL MONTANA MONDAY
AND TUESDAY AFTERNOON. LATEST OBSERVED 10/100/1000 HOUR FUELS AND
FIRE DANGERS DO NOT SUPPORT ISSUING ANY HIGHLIGHTS AT THIS TIME.
HOWEVER...EXPECT THAT THESE VALUES WILL CHANGE RAPIDLY OVER THE NEXT
FEW DAYS. MPJ

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  52  86  54  90 /  10   0   0  10
CTB  50  81  53  83 /  20   0   0  10
HLN  53  87  55  91 /  20   0   0  10
BZN  49  88  50  92 /  10  10  10  10
WEY  35  74  38  78 /  10  10  10  10
DLN  46  80  48  84 /  20   0   0  10
HVR  52  90  53  93 /  10   0   0   0
LWT  50  84  51  88 /  20   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...MPJ
LONG TERM...SUK/WILLIAMSON DC
AVIATION...GUSTAFSON

WEATHER.GOV/GREATFALLS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
439 AM MDT SUN AUG 9 2009

MTZ008>015-044>055-101045-
BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL-
CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-
TOOLE-LIBERTY-EASTERN PONDERA-BLAINE-
SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN-FERGUS-
JEFFERSON-BROADWATER-MEAGHER-GALLATIN-
439 AM MDT SUN AUG 9 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
332 PM MDT SUN AUG 9 2009

MTZ010-044-046-092215-
EASTERN GLACIER MT-EASTERN PONDERA MT-TOOLE MT-
332 PM MDT SUN AUG 9 2009

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN PONDERA...EASTERN
GLACIER AND CENTRAL TOOLE COUNTIES UNTIL 415 PM MDT...

AT 330 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
AN AREA OF STRONG THUNDERSTORMS NEAR SHELBY...MOVING SOUTHEAST AT 25
MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THESE STORMS...ALONG WITH HEAVY RAIN.

LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...SHELBY.

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

LAT...LON 4856 11131 4830 11197 4875 11233 4889 11193
TIME...MOT...LOC 2131Z 326DEG 5KT 4854 11188

MLS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
508 PM MDT SUN AUG 9 2009

MTZ010-044>046-092345-
EASTERN GLACIER MT-EASTERN PONDERA MT-LIBERTY MT-TOOLE MT-
508 PM MDT SUN AUG 9 2009

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN PONDERA...EASTERN
GLACIER...TOOLE AND WESTERN LIBERTY COUNTIES UNTIL 545 PM MDT...

AT 505 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A CLUSTER OF SLOW-MOVING STRONG THUNDERSTORMS EXTENDING FROM FAR
EASTERN GLACIER COUNTY INTO TOOLE COUNTY...MOVING SOUTHEAST AT 15
MPH.

VERY HEAVY RAIN AND HAIL UP TO THE SIZE OF PENNIES ARE EXPECTED WITH
THESE STORMS.

LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...SHELBY...KEVIN...
ETHRIDGE...OILMONT AND FERDIG.

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING AND DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER
COVERS THE ROADWAY.

LAT...LON 4869 11123 4828 11186 4880 11250 4901 11208
      4900 11179
TIME...MOT...LOC 2305Z 300DEG 5KT 4867 11206

MLS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
521 PM MDT SUN AUG 9 2009

MTZ012-013-049-100000-
CASCADE MT-CHOUTEAU MT-EASTERN TETON MT-
521 PM MDT SUN AUG 9 2009

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN TETON...NORTHERN CASCADE
AND WESTERN CHOUTEAU COUNTIES UNTIL 600 PM MDT...

AT 519 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 13 MILES NORTHWEST OF BLACK EAGLE...OR 14 MILES
NORTH OF GREAT FALLS...MOVING SOUTHEAST AT 20 MPH.

HEAVY RAIN AND HAIL UP TO THE SIZE OF PENNIES IS EXPECTED WITH THIS
STORM.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...BLACK EAGLE.

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

LAT...LON 4770 11106 4749 11124 4766 11160 4782 11147
TIME...MOT...LOC 2320Z 302DEG 13KT 4769 11140

MLS