000
FXUS65 KGGW 210948
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
348 AM MDT TUE MAY 21 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
THE SHORT TERM BEGINS WITH THE UPPER LOW OVER THE EASTERN DAKOTAS
SLOWLY MOVING EAST ALLOWING A SHORT LIVED RIDGE TO SLIDE OVER
NORTHEASTERN MONTANA. BY THE END OF THE SHORT TERM ON THURSDAY
ANOTHER UPPER LOW BEGINS TO SLIDE CLOSER TO THE REGION.
THE SHORT TERM WILL FEATURE SLIGHTLY WARMER TEMPERATURES...BUT NOT
MAJOR INCREASE. A FEW SHOWERS TODAY IN THE SOUTHEAST AND DRY
CONDITIONS ELSEWHERE.
WEDNESDAY AND THURSDAY THE APPROACHING UPPER LOW TO THE WEST WILL
START A STEADY RAMPING UP OF EASTERLY WINDS ACROSS THE REGION
WHICH WILL LIKELY REQUIRE A LAKE WIND ADVISORY.
THURSDAY AFTERNOON HAS A POSSIBILITY OF SOME THUNDER IN THE
WESTERN ZONES...HOWEVER CONDITIONS ARE NOT THAT FAVORABLE FOR ANY
FORMING CONVECTION TO MOVE TOO FAR INTO THE REGION. PROTON
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE EXTENDED PERIOD BEGINS THURSDAY NIGHT WITH A CLOSED UPPER
TROUGH ACROSS THE WEST AND AN UPPER LEVEL RIDGE ACROSS THE
SOUTHERN U.S. THAT EXTENDS THROUGH THE PLAINS. THIS PLACES
NORTHEAST MONTANA IN DIFFLUENT SOUTHWEST FLOW ALOFT. THE 00Z MODEL
SUITE IS POINTING TO A ROBUST SHORTWAVE PUSHING THROUGH THE FLOW
WHICH COULD LEAD TO ENHANCED DYNAMIC LIFT ACROSS PARTS OF THE CWA.
THE 850MB LEVEL EASTERLY/SOUTHEASTERLY WINDS WILL HELP TO PUMP IN
LOW LEVEL MOISTURE...AND ALSO SUGGEST THE PRESENCE OF A LOW LEVEL
JET WHICH COULD HELP TO FORCE CONVECTION IF THE OTHER DYNAMIC
INGREDIENTS DISCUSSED COME TOGETHER COINCIDENT LY. DECENT
EQUIVALENT POTENTIAL TEMPERATURE RIDGE LOOKS TO BE IN PLACE ACROSS
THE CWA BY FRIDAY AFTERNOON WITH WARMING TEMPERATURES OUT AHEAD OF
THE TROUGH. THE MID LEVELS ALSO LOOK PRETTY DRY. THIS LEADS TO THE
CONCERN THAT SOME STORMS THAT DEVELOP MAY PRODUCE HAIL. THE 00Z
ECMWF FORECAST SOUNDINGS SHOW LI BETWEEN -1 AND 1 ACROSS THE CWA
AND TOTAL TOTALS IN THE UPPER 40S AND NOT MUCH CAPE. NOTICE A NICE
VEERING PROFILE IN THE ECMWF FORECAST SOUNDINGS WITH ABOUT 40 KTS
OF 0-6 KM SPEED SHEAR. THE GFS SHOWS ACTUALLY HIGHER LIFTED INDEX
VALUES AND IS LESS SUGGESTIVE OF STRONG CONVECTION IN SHORT...THE
INGREDIENTS ARE THERE FOR GOOD THUNDERSTORM DEVELOPMENT BUT SOME
PARAMETERS APPEAR ONLY MARGINAL AND SO CONFIDENCE ON STRONG STORMS
IS NOT YET THERE. WILL NEED TO LOOK AT FUTURE MODEL RUNS FOR
CONSISTENCY. TIMING OF THE SHORTWAVE AS IT INTERSECTS THE THETA-E
RIDGE WILL ALSO BE KEY...RIGHT NOW IT APPEARS THE NORTHERN ZONES
AND SOUTHERN SASKATCHEWAN MAY BE IN THE BEST LOCATION FOR FRIDAY
AFTERNOON FOR CONVECTION INITIATION IF FOLLOWING THE EC GUIDANCE.
ANY CONVECTION SHOULD SLOWLY DWINDLE FRIDAY NIGHT WITH THE LOSS OF
DAYTIME HEATING.
ON SATURDAY...UPPER FLOW PATTERN MAINTAINS SOUTHWEST FLOW ALOFT
OVER THE CWA WITH RIDGE AXIS RUNNING FROM TEXAS...NORTHWESTWARD
THROUGH THE PLAINS AND INTO NE MT. THIS SHOULD ACTUALLY LEAD TO
WARMER TEMPERATURES WHICH COULD LEND TO ENHANCING THE POTENTIAL
FOR CONVECTION INITIATION. NICE UPPER LEVEL DIFFLUENCE IS NOTED
AND SOME OF THE FORECAST SOUNDINGS ARE CERTAINLY INDICATIVE OF
CONVECTIVE POTENTIAL. THERE IS ALSO SOME SUBTLE EMBEDDED SHORTWAVE
ENERGY THAT PUSHES THROUGH SHORTWAVE FLOW ALOFT...BUT NOTHING AS
IMPRESSIVE AS THE WAVE ON FRIDAY.
SUNDAY INTO SUNDAY NIGHT PRESENTLY LOOKS TO BE THE BEST POTENTIAL
FOR THUNDERSTORMS TO DEVELOP WHICH COULD BECOME STRONG IN NATURE.
THERE IS MUCH BETTER AGREEMENT IN BOTH THE ECMWF AND GFS WITH BOTH
FORECAST SOUNDINGS SHOWING LIFTED INDEX VALUES BETWEEN -5 AND -8
ACROSS THE CWA. THE GFS BUFKIT SOUNDING SHOWS AROUND 1500 J/KG OF
CAPE AND TOTAL TOTALS APPROACHING 60. THOUGH A NICE VEERING WIND
PROFILE EXISTS IN BOTH ECMWF/GFS SOUNDINGS... THOUGH WOULD LIKE
TO SEE MORE SPEED SHEAR IN THE SOUNDINGS. SHOULD ALSO POINT OUT
THAT FORECAST SOUNDINGS FROM BOTH MODELS ARE SHOWING PWATS OF OVER
AN INCH. WITH AGAIN DRY AIR PRESENT IN THE MID LEVELS...WOULD BE
CONCERNED ABOUT HAIL FORMATION WITH ANY STORMS. THERE IS AGAIN A
LOW LEVEL 850MB EASTERLY JET THAT FORMS...WHICH SHOULD HELP TO
PUMP IN LOW LEVEL MOISTURE. NICE THETA-E RIDGE AXIS OVER THE CWA
ALONG WITH A COUPLE OF SHORTWAVES THAT PASS OFF TO THE WEST COULD
ALSO HELP PROVIDE DECENT LIFT IF THE TIMING IS RIGHT...AND THAT
WILL BE THE KEY FOR DETERMINING THE OVERALL EXTENT OF THE
THUNDERSTORM POTENTIAL. OF ALL OF THE DAYS IN THE EXTENDED
PERIOD...THIS LOOKS TO BE THE ONE WITH THE BEST MODEL AGREEMENT
AND THE BEST IN TERMS OF VARIOUS INGREDIENTS COMING TOGETHER BOTH
DYNAMICALLY AND THERMODYNAMICALLY THAT ARE COINCIDENT WITH EACH
OTHER. WILL OF COURSE NEED TO WATCH FOR CONTINUITY IN THE MODEL
SOLUTIONS TO DETERMINE IF THIS CONTINUES. WILL ALSO NEED TO HONE
IN ON MESOSCALE DETAILS WHICH ARE DIFFICULT TO DETERMINE THIS FAR
IN ADVANCE. WHERE THESE INGREDIENTS COME TOGETHER...THE PRECISE
TIMING OF THE SHORTWAVE FEATURES...AND HOW EVERYTHING INTERACTS
WITH MESOSCALE PROCESSES WILL DETERMINE THE PRECISE EXTENT OF
CONVECTIVE POTENTIAL.
MONDAY AND BEYOND...NE MT IS EXPECTED TO REMAIN IN SOUTHWEST FLOW
ALOFT WITH THE ECMWF GUIDANCE SUGGESTING PERHAPS THE UPPER
PATTERN COULD BECOME MORE ZONAL LATE NEXT WEEK. THE GFS ON THE
OTHER HAND KEEPS THE OVERALL PATTERN ALOFT FROM THE SOUTHWEST. THIS
OVERALL PATTERN WOULD BE CONSIDERED FAVORABLE FOR A CONTINUED
POTENTIAL FOR CONVECTIVE SHOWERS AND THUNDERSTORMS TO DEVELOP
DEPENDING ON TIMING/TRACK OF SHORTWAVE FEATURES IN THE FLOW. MALIAWCO.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL OF THE TAF SITES.
SOME RAIN SHOWERS ARE POSSIBLE AT KSDY AND KGDY THROUGH THIS
EVENING...BUT SHOULD NOT LEAD TO A REDUCTION IN EITHER CEILINGS OR
VISIBILITIES ENOUGH TO AFFECT GROUND OPERATIONS. SURFACE WINDS
TODAY WILL BE OUT OF THE NORTHEAST FROM 10 TO 20 KTS...BECOMING
EASTERLY AT AROUND 10 KTS OVERNIGHT. MALIAWCO
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 210126
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
726 PM MDT MON MAY 20 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
THE RAIN HAS PRETTY MUCH PUSHED TO OUR SOUTH IN THE PAST COUPLE OF
HOURS BUT ANOTHER ROUND LOOKS TO MAKE ANOTHER DASH LATER TONIGHT...
SO HIGHER POPS IN THE EAST FOR LATE TONIGHT LOOK GOOD. LOWERED
TEMPS A TAD FOR TONIGHT AS DRY AIR FROM THE NORTH WILL CONTINUE TO
FLOW IN. OTHERWISE...LAKE WIND ADVISORY WAS CANCELLED AND WINDS
WERE DECREASED FOR THE EVENING HOURS. JAMBA
PREVIOUS DISCUSSION...
LARGE UPPER LOW OVER THE UPPER MIDWEST CONTINUES TO PUSH RAIN BACK
INTO EASTERN MONTANA THIS AFTERNOON. NOT MUCH MOVEMENT EXPECTED
WITH THE SYSTEM UNTIL TUESDAY NIGHT WHEN ANOTHER STRONG UPPER LOW
PUSHES INTO THE PACIFIC NORTHWEST. DRIER AIR WRAPPING INTO THE
NORTHWEST SIDE OF THE SYSTEM BEGINNING TO PUSH RAIN SOUTHWARD BUT
EXPECT SHOWERS TO CONTINUE IN THE VICINITY OF THE LOWER
YELLOWSTONE VALLEY THROUGH TUESDAY.
OMEGA BLOCK LIKE PATTERN DEVELOPS ON TUESDAY WITH THE LOW OVER THE
UPPER MIDWEST AND THE LOW OVER THE PACIFIC NORTHWEST AND PINCHED
RIDGE OVER MONTANA. THIS WILL RESULT IN DRY WEATHER WITH HIGH
PRESSURE PUSHING INTO THE NORTHERN PLAINS INTO WEDNESDAY. EBERT
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE PERIOD BEGINS WITH EASTERN MONTANA UNDER A NARROW RIDGE AND
MILD CONDITIONS BETWEEN TWO LOW PRESSURE SYSTEMS. THE SYSTEM TO
THE WEST...A CLOSED LOW SPINNING OVER WASHINGTON/OREGON WILL BEGIN
TO LIFT INTO WESTERN CANADA THURSDAY. THIS MOVEMENT WILL SEND A
COLD FRONT OVER THE MONTANA PRAIRIE THURSDAY NIGHT. FRIDAY THE
FRONT SWINGS ACROSS EASTERN MONTANA WHERE IT WILL MEET UP WITH
UNSTABLE AIR. MODELS SEEM TO INDICATE EARLY THAT A LINE OF
THUNDERSTORMS COULD DEVELOP FRIDAY AFTERNOON AND DUMP RAIN AND
POSSIBLY HAIL. THE SOUTHWEST FLOW ALOFT WILL KEEP DIRECTING MOIST
WARM AIR INTO THE REGION TO CREATE MORE INSTABILITY FOR SATURDAY
AND SUNDAY. SO THE WEEKEND LOOKS STORMY WITH POSSIBLE STRONG
THUNDERSTORMS. A SECONDARY TROUGH WILL SEND MORE SHOWERS OUR WAY
INTO EARLY NEXT WEEK.
INHERITED GRID MATCH UP WITH MODEL TRENDS FOR THUNDERSTORMS
THROUGH THE WEEKEND...SO FEW GRID EDITS NEEDED...MAINLY TO
ADJUST WX GRIDS BASED ON INSTABILITY PEAKS. WITH SOUTHWEST FLOW
ALOFT...TEMPERATURES MIGHT TREND SLIGHTLY ABOVE NORMAL...BUT BIAS
ADJUSTED TEMPERATURES ARE LIKELY TO CHANGE. SO LEFT TEMPERATURE
GRIDS AS IS FOR NOW. SCT
...PREVIOUS DISCUSSION...
THE EXTENDED FEATURES MORE SOUTHWEST FLOW THROUGH THE PERIOD. MOST
DAYS SLIGHT CHANCES OF THUNDERSTORMS SLIDING OFF THE CENTRAL
MONTANA MOUNTAINS INTO THE PLAINS FOR HIGHER POPS WEST AND LOW
POPS EAST. FOR THE WEEKEND THE UPPER LOW BREAKS A GOOD WAVE OFF
AND DRIVES IT THROUGH NORTHEAST MONTANA FOR A BETTER CHANCE OF
THUNDERSTORMS THEREFORE BUMPED UP POPS A TAD FOR THOSE PERIODS.
TEMPERATURES WILL HOLD IN NEAR NORMAL THROUGH THE PERIOD.
MODEL TRENDS ARE SHOWING LOWERING HEIGHTS ON THE GFS FOR NORTHEAST
MONTANA WHICH LEADS TO THE UPPER LOW MOVING TOWARDS THE EAST. IF
THE TREND CONTINUES THEN LIKELY POPS ARE A GOOD BET FOR THE
WEEKEND WITH ELEVATED CONFIDENCE. RMOP/ENSEMBLES ARE SHOWING THAT
ITS A GOOD BET THAT AT SOME POINT THIS UPCOMING WEEKEND FOR A
STRONG THUNDERSTORM EVENT ACROSS EASTERN MONTANA. PROTON
&&
.AVIATION...
AS THE LOW CENTER MOVES INTO THE EASTERN DAKOTAS...HIGH PRESSURE
MOVES INTO NORTHEASTERN MONTANA FROM THE WEST TONIGHT. THIS WILL
BRING CLEARING TO KGGW AND POSSIBLY KOLF...PLUS ALL AREAS TO THE
WEST. THE LOW STRATUS DECK WILL LINGER TONIGHT AND TUESDAY MORNING
OVER ALL OF THE DAKOTAS AND FAR EASTERN AREAS OF NORTHEAST
MONTANA. SO SHOWERS AND LOW STRATUS ARE STILL POSSIBLE AT KOLF
BUT LIKELY OVER KSDY AND KGDV WHERE CEILINGS COULD REMAIN MVFR.
THE STRONG NORTHERLY WIND OF 15G25KTS WILL ALSO LINGER OVER KSDY
AND KGDV THIS EVENING...WITH LESSER STRENGTHS TO THE WEST. LATE
TONIGHT NORTH WIND WILL DIMINISH TO 10-15KTS. TUESDAY WIND WILL
VEER TO THE NORTHEAST...THEN EAST. SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 202222
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
422 PM MDT MON MAY 20 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
LARGE UPPER LOW OVER THE UPPER MIDWEST CONTINUES TO PUSH RAIN BACK
INTO EASTERN MONTANA THIS AFTERNOON. NOT MUCH MOVEMENT EXPECTED
WITH THE SYSTEM UNTIL TUESDAY NIGHT WHEN ANOTHER STRONG UPPER LOW
PUSHES INTO THE PACIFIC NORTHWEST. DRIER AIR WRAPPING INTO THE
NORTHWEST SIDE OF THE SYSTEM BEGINNING TO PUSH RAIN SOUTHWARD BUT
EXPECT SHOWERS TO CONTINUE IN THE VICINITY OF THE LOWER
YELLOWSTONE VALLEY THROUGH TUESDAY.
OMEGA BLOCK LIKE PATTERN DEVELOPS ON TUESDAY WITH THE LOW OVER THE
UPPER MIDWEST AND THE LOW OVER THE PACIFIC NORTHWEST AND PINCHED
RIDGE OVER MONTANA. THIS WILL RESULT IN DRY WEATHER WITH HIGH
PRESSURE PUSHING INTO THE NORTHERN PLAINS INTO WEDNESDAY. EBERT
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE PERIOD BEGINS WITH EASTERN MONTANA UNDER A NARROW RIDGE AND
MILD CONDITIONS BETWEEN TWO LOW PRESSURE SYSTEMS. THE SYSTEM TO
THE WEST...A CLOSED LOW SPINNING OVER WASHINGTON/OREGON WILL BEGIN
TO LIFT INTO WESTERN CANADA THURSDAY. THIS MOVEMENT WILL SEND A
COLD FRONT OVER THE MONTANA PRAIRIE THURSDAY NIGHT. FRIDAY THE
FRONT SWINGS ACROSS EASTERN MONTANA WHERE IT WILL MEET UP WITH
UNSTABLE AIR. MODELS SEEM TO INDICATE EARLY THAT A LINE OF
THUNDERSTORMS COULD DEVELOP FRIDAY AFTERNOON AND DUMP RAIN AND
POSSIBLY HAIL. THE SOUTHWEST FLOW ALOFT WILL KEEP DIRECTING MOIST
WARM AIR INTO THE REGION TO CREATE MORE INSTABILITY FOR SATURDAY
AND SUNDAY. SO THE WEEKEND LOOKS STORMY WITH POSSIBLE STRONG
THUNDERSTORMS. A SECONDARY TROUGH WILL SEND MORE SHOWERS OUR WAY
INTO EARLY NEXT WEEK.
INHERITED GRID MATCH UP WITH MODEL TRENDS FOR THUNDERSTORMS
THROUGH THE WEEKEND...SO FEW GRID EDITS NEEDED...MAINLY TO
ADJUST WX GRIDS BASED ON INSTABILITY PEAKS. WITH SOUTHWEST FLOW
ALOFT...TEMPERATURES MIGHT TREND SLIGHTLY ABOVE NORMAL...BUT BIAS
ADJUSTED TEMPERATURES ARE LIKELY TO CHANGE. SO LEFT TEMPERATURE
GRIDS AS IS FOR NOW. SCT
...PREVIOUS DISCUSSION...
THE EXTENDED FEATURES MORE SOUTHWEST FLOW THROUGH THE PERIOD. MOST
DAYS SLIGHT CHANCES OF THUNDERSTORMS SLIDING OFF THE CENTRAL
MONTANA MOUNTAINS INTO THE PLAINS FOR HIGHER POPS WEST AND LOW
POPS EAST. FOR THE WEEKEND THE UPPER LOW BREAKS A GOOD WAVE OFF
AND DRIVES IT THROUGH NORTHEAST MONTANA FOR A BETTER CHANCE OF
THUNDERSTORMS THEREFORE BUMPED UP POPS A TAD FOR THOSE PERIODS.
TEMPERATURES WILL HOLD IN NEAR NORMAL THROUGH THE PERIOD.
MODEL TRENDS ARE SHOWING LOWERING HEIGHTS ON THE GFS FOR NORTHEAST
MONTANA WHICH LEADS TO THE UPPER LOW MOVING TOWARDS THE EAST. IF
THE TREND CONTINUES THEN LIKELY POPS ARE A GOOD BET FOR THE
WEEKEND WITH ELEVATED CONFIDENCE. RMOP/ENSEMBLES ARE SHOWING THAT
ITS A GOOD BET THAT AT SOME POINT THIS UPCOMING WEEKEND FOR A
STRONG THUNDERSTORM EVENT ACROSS EASTERN MONTANA. PROTON
&&
.AVIATION...
AS THE LOW CENTER MOVES INTO THE EASTERN DAKOTAS...HIGH PRESSURE
MOVES INTO NORTHEASTERN MONTANA FROM THE WEST TONIGHT. THIS WILL
BRING CLEARING TO KGGW AND POSSIBLY KOLF...PLUS ALL AREAS TO THE
WEST. THE LOW STRATUS DECK WILL LINGER TONIGHT AND TUESDAY MORNING
OVER ALL OF THE DAKOTAS AND FAR EASTERN AREAS OF NORTHEAST
MONTANA. SO SHOWERS AND LOW STRATUS ARE STILL POSSIBLE AT KOLF
BUT LIKELY OVER KSDY AND KGDV WHERE CEILINGS COULD REMAIN MVFR.
THE STRONG NORTHERLY WIND OF 15G25KTS WILL ALSO LINGER OVER KSDY
AND KGDV THIS EVENING...WITH LESSER STRENGTHS TO THE WEST. LATE
TONIGHT NORTH WIND WILL DIMINISH TO 10-15KTS. TUESDAY WIND WILL
VEER TO THE NORTHEAST...THEN EAST. SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 201515
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
915 AM MDT MON MAY 20 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
RAINFALL CONTINUES OVER THE EASTERN HALF OF THE CWA THIS MORNING.
MADE A FEW FURTHER ADJUSTMENTS TO THE WESTERN EDGE OF HIGH POPS
WITH EXPECTATION THAT RAIN WILL STAY TO THE EAST OF GLASGOW AND
JORDAN. SIMILAR ADJUSTMENTS ALSO MADE FOR TONIGHT WITH THE UPPER
LOW BEGINNING TO SHIFT EASTWARD. EBERT
6AM UPDATE...THE WESTERN PUSH OF RAIN LOOKS TO FALL SHORT OF
GLASGOW THEREFORE BACKED DOWN THE 100 POPS. PROTON
PREVIOUS SHORT TERM DISCUSSION...TODAY AND TONIGHT...A VERTICALLY
STACKED LOW PRESSURE SYSTEM SITUATED OVER THE DAKOTAS WILL
CONTINUE TO SIT AND SPIN. AS IT DOES...A SHIELD OF STRATIFORM RAIN
WILL CONTINUE TO RETROGRADE FROM EAST TO WEST THOUGH THE
DAY...BEFORE CRASHING BACK TO THE SOUTHEAST THIS AFTERNOON AND
EVENING AS THE LOW BEGINS TO TRANSLATE EASTWARD. DETERMINING THE
MAXIMUM EXTENT OF THE BACK EDGE OF THE RAINFALL SHIELD WILL
CONTINUE TO BE THE MAIN FORECAST CHALLENGE.
THE LATEST NAM HAD THE PRECIPITATION INITIALIZED A BIT FURTHER TO
THE EAST THAN RADAR OBSERVATIONS SHOWED. THUS...FEEL THE
PRECIPITATION SHIELD SHOULD MAKE IT A BIT FURTHER THAN THIS
SOLUTION IS SUGGESTING. THE 00Z ECMWF AND GFS HAVE A LITTLE BETTER
HANDLE ON IT. WILL ADMIT THAT THE HRRR HAS BEEN AN IMPRESSIVE
INFORMER AS IT CAUGHT ONTO THE IDEA THAT THE SHIELD WOULD STOP
RETROGRADING FOR A FEW HOURS OVERNIGHT BEFORE AGAIN PROCEEDING ITS
MARCH FURTHER WEST TOWARD MORNING AND THIS IS WHAT IS OCCURRING.
LENDING FURTHER SUPPORT TO THE GUIDANCE IS THE OBSERVATION OF
RECENT PRESSURE FALLS ACROSS THE CWA. PRESSURES ARE GENERALLY
FALLING BETWEEN 0.5 AND 1 MB PER HOUR FOR THE LAST FEW HOURS.
THEREFORE...WILL FEEL COMFORTABLE WITH A BLEND OF THE
ECMWF/GFS/HRRR MODEL SOLUTIONS FOR DETERMINING A BEST GUESS AS TO
WHERE THE BACK EDGE WILL REACH BEFORE IT BEGINS TO PUSH BACK TO
THE SOUTHEAST. THIS BRINGS IT TO A LINE FROM ABOUT OPHEIM...EXTENDING
SOUTH THROUGH JUST WEST OF GLASGOW...TO THE JORDAN AREA. TO THE
EAST OF THIS LINE...THERE IS A DECENT CHANCE AT A NICE WETTING
RAIN THROUGH TONIGHT. IN FACT...WOULD NOT BE SURPRISED IF SOME
AREAS SEE ONE TO TWO INCHES OF RAINFALL ACCUMULATION BY THE END OF
TONIGHT AND INCLUDED A MENTION OF HEAVY RAIN IN SOME OF THE
EASTERN ZONES THROUGH THE MORNING. TO THE WEST OF THIS LINE...RAIN
CHANCES WILL ONLY BE SHOWERY IN NATURE WITH A FEW HUNDREDTHS OF AN
INCH OF ACCUMULATION THE ABSOLUTE MOST THAT WOULD OCCUR. PRECISE
RAINFALL AMOUNTS WILL DEPEND UPON THE PRECISE LOCATION OF WHERE
THE BACK EDGE OF THIS RAIN SHIELD WINDS UP...AS WELL AS SOME FINER
MESOSCALE DETAILS THAT ARE DIFFICULT TO DETERMINE WITH MUCH
CONFIDENCE. TEMPERATURES ARE KEPT AROUND OR JUST BELOW SEASONAL
NORMALS DUE TO THE PRESENCE OF THE LINGERING UPPER TROUGH.
THE OTHER CONCERN TODAY WILL BE STRONG GUSTY WINDS DUE TO A SHARP
PRESSURE GRADIENT IN ASSOCIATION WITH THE SURFACE LOW ACROSS THE
DAKOTAS. AM EXPECTING THAT THE TIGHT PACKING OF THE ISOBARS COULD
SUPPORT NORTHERLY WINDS ON THE ORDER OF 20 TO 30 MPH WITH SOME
GUSTS EXCEEDING 40 MPH THIS AFTERNOON AND EVENING. WILL HOIST A
LAKE WIND ADVISORY FROM NOON UNTIL 9PM DUE TO THIS CONCERN. THIS
MAY ALSO LEAD TO WIND DRIVEN RAINS IN SOME LOCATIONS WHICH COULD
POSE AS HAZARDS TO TRAVELERS AND PEDESTRIANS ALIKE.
TONIGHT THROUGH WEDNESDAY...THE LOW PRESSURE SYSTEM OVER THE
DAKOTAS VERY GRADUALLY TRANSLATES EASTWARD...SO CONTINUED TO TREND
POPS DOWN AND HAVE PRECIPITATION SHUTTING OFF FROM WEST TO EAST.
WILL LEAVE ONLY A SLIGHT CHANCE OF RAIN SHOWERS IN THE EXTREME SE
ZONES BY LATE TUESDAY NIGHT. ON WEDNESDAY...ANOTHER UPPER TROUGH
WITH CLOSED LOW MOVES INTO THE PACIFIC NORTHWEST AS IT DOES
SO...DIFFLUENT SOUTHWEST FLOW ALOFT IS EXPECTED TO DEVELOP ACROSS
THE CWA. THIS MAY LEAD TO CONVECTIVE SHOWERS ON WEDNESDAY...MAINLY
ACROSS THE SW ZONES. SOME OF THE SOUNDINGS IN THE NAM BUFKIT JUST
WEST OF THE CWA ARE SHOWING TOTAL TOTALS APPROACHING 50 AND LI
BECOMING NEGATIVE. DID NOT INSERT A MENTION OF THUNDER JUST YET DUE TO THE
FACT THAT THE PRIMARY FOCUS WAS ON THE CURRENT RAINFALL SITUATION
AND LAKE WIND POTENTIAL. HOWEVER...FUTURE SHIFTS MAY WANT TO
EVALUATE THE POTENTIAL FOR ANY CONVECTIVE INITIATION TOWARD THE
MIDDLE OF THE WEEK. MALIAWCO
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE EXTENDED FEATURES MORE SOUTHWEST FLOW THROUGH THE PERIOD. MOST
DAYS SLIGHT CHANCES OF THUNDERSTORMS SLIDING OFF THE CENTRAL
MONTANA MOUNTAINS INTO THE PLAINS FOR HIGHER POPS WEST AND LOW
POPS EAST. FOR THE WEEKEND THE UPPER LOW BREAKS A GOOD WAVE OFF
AND DRIVES IT THROUGH NORTHEAST MONTANA FOR A BETTER CHANCE OF
THUNDERSTORMS THEREFORE BUMPED UP POPS A TAD FOR THOSE PERIODS.
TEMPERATURES WILL HOLD IN NEAR NORMAL THROUGH THE PERIOD.
MODEL TRENDS ARE SHOWING LOWERING HEIGHTS ON THE GFS FOR NORTHEAST
MONTANA WHICH LEADS TO THE UPPER LOW MOVING TOWARDS THE EAST. IF
THE TREND CONTINUES THEN LIKELY POPS ARE A GOOD BET FOR THE
WEEKEND WITH ELEVATED CONFIDENCE. RMOP/ENSEMBLES ARE SHOWING THAT
ITS A GOOD BET THAT AT SOME POINT THIS UPCOMING WEEKEND FOR A
STRONG THUNDERSTORM EVENT ACROSS EASTERN MONTANA. PROTON
&&
.AVIATION...
MVFR VISIBILITY FROM RAIN WITH MVFR/IFR CEILINGS FOR THE EASTERN
AREAS INCLUDING KSDY AND KGDV THROUGH THE PERIOD AS THEY ARE
CLOSER TO THE LOW OVER SOUTHEASTERN NORTH DAKOTA WHICH IS WRAPPING
AROUND MOISTURE INTO THE LOWER YELLOWSTONE RIVER VALLEY. THIS
TREND LOOKS TO CONTINUE THROUGH THE PERIOD.
VFR FOR WESTERN AREAS INCLUDING KGGW AND KOLF THROUGH THE PERIOD
THE MVFR/IFR CEILING SHIELD LOOKS TO STAY JUST OFF TO THE EAST.
FOR NOW WILL STAY WITH VFR CEILINGS.
WIND WILL BE MORE OF AN ISSUE FOR THE EASTERN SITES WITH THE WINDS
STAYING UP ABOVE 20 KNOTS THROUGH THE END OF THE TAF PERIOD.
PROTON/SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 201153
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
553 AM MDT MON MAY 20 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
6AM UPDATE...THE WESTERN PUSH OF RAIN LOOKS TO FALL SHORT OF
GLASGOW THEREFORE BACKED DOWN THE 100 POPS. PROTON
TODAY AND TONIGHT...A VERTICALLY STACKED LOW PRESSURE SYSTEM
SITUATED OVER THE DAKOTAS WILL CONTINUE TO SIT AND SPIN. AS IT
DOES...A SHIELD OF STRATIFORM RAIN WILL CONTINUE TO RETROGRADE
FROM EAST TO WEST THOUGH THE DAY...BEFORE CRASHING BACK TO THE
SOUTHEAST THIS AFTERNOON AND EVENING AS THE LOW BEGINS TO
TRANSLATE EASTWARD. DETERMINING THE MAXIMUM EXTENT OF THE BACK
EDGE OF THE RAINFALL SHIELD WILL CONTINUE TO BE THE MAIN FORECAST
CHALLENGE.
THE LATEST NAM HAD THE PRECIPITATION INITIALIZED A BIT FURTHER TO
THE EAST THAN RADAR OBSERVATIONS SHOWED. THUS...FEEL THE
PRECIPITATION SHIELD SHOULD MAKE IT A BIT FURTHER THAN THIS
SOLUTION IS SUGGESTING. THE 00Z ECMWF AND GFS HAVE A LITTLE BETTER
HANDLE ON IT. WILL ADMIT THAT THE HRRR HAS BEEN AN IMPRESSIVE
INFORMER AS IT CAUGHT ONTO THE IDEA THAT THE SHIELD WOULD STOP
RETROGRADING FOR A FEW HOURS OVERNIGHT BEFORE AGAIN PROCEEDING ITS
MARCH FURTHER WEST TOWARD MORNING AND THIS IS WHAT IS OCCURRING.
LENDING FURTHER SUPPORT TO THE GUIDANCE IS THE OBSERVATION OF
RECENT PRESSURE FALLS ACROSS THE CWA. PRESSURES ARE GENERALLY
FALLING BETWEEN 0.5 AND 1 MB PER HOUR FOR THE LAST FEW HOURS.
THEREFORE...WILL FEEL COMFORTABLE WITH A BLEND OF THE
ECMWF/GFS/HRRR MODEL SOLUTIONS FOR DETERMINING A BEST GUESS AS TO
WHERE THE BACK EDGE WILL REACH BEFORE IT BEGINS TO PUSH BACK TO
THE SOUTHEAST. THIS BRINGS IT TO A LINE FROM ABOUT OPHEIM...EXTENDING
SOUTH THROUGH JUST WEST OF GLASGOW...TO THE JORDAN AREA. TO THE
EAST OF THIS LINE...THERE IS A DECENT CHANCE AT A NICE WETTING
RAIN THROUGH TONIGHT. IN FACT...WOULD NOT BE SURPRISED IF SOME
AREAS SEE ONE TO TWO INCHES OF RAINFALL ACCUMULATION BY THE END OF
TONIGHT AND INCLUDED A MENTION OF HEAVY RAIN IN SOME OF THE
EASTERN ZONES THROUGH THE MORNING. TO THE WEST OF THIS LINE...RAIN
CHANCES WILL ONLY BE SHOWERY IN NATURE WITH A FEW HUNDREDTHS OF AN
INCH OF ACCUMULATION THE ABSOLUTE MOST THAT WOULD OCCUR. PRECISE
RAINFALL AMOUNTS WILL DEPEND UPON THE PRECISE LOCATION OF WHERE
THE BACK EDGE OF THIS RAIN SHIELD WINDS UP...AS WELL AS SOME FINER
MESOSCALE DETAILS THAT ARE DIFFICULT TO DETERMINE WITH MUCH
CONFIDENCE. TEMPERATURES ARE KEPT AROUND OR JUST BELOW SEASONAL
NORMALS DUE TO THE PRESENCE OF THE LINGERING UPPER TROUGH.
THE OTHER CONCERN TODAY WILL BE STRONG GUSTY WINDS DUE TO A SHARP
PRESSURE GRADIENT IN ASSOCIATION WITH THE SURFACE LOW ACROSS THE
DAKOTAS. AM EXPECTING THAT THE TIGHT PACKING OF THE ISOBARS COULD
SUPPORT NORTHERLY WINDS ON THE ORDER OF 20 TO 30 MPH WITH SOME
GUSTS EXCEEDING 40 MPH THIS AFTERNOON AND EVENING. WILL HOIST A
LAKE WIND ADVISORY FROM NOON UNTIL 9PM DUE TO THIS CONCERN. THIS
MAY ALSO LEAD TO WIND DRIVEN RAINS IN SOME LOCATIONS WHICH COULD
POSE AS HAZARDS TO TRAVELERS AND PEDESTRIANS ALIKE.
TONIGHT THROUGH WEDNESDAY...THE LOW PRESSURE SYSTEM OVER THE
DAKOTAS VERY GRADUALLY TRANSLATES EASTWARD...SO CONTINUED TO TREND
POPS DOWN AND HAVE PRECIPITATION SHUTTING OFF FROM WEST TO EAST.
WILL LEAVE ONLY A SLIGHT CHANCE OF RAIN SHOWERS IN THE EXTREME SE
ZONES BY LATE TUESDAY NIGHT. ON WEDNESDAY...ANOTHER UPPER TROUGH
WITH CLOSED LOW MOVES INTO THE PACIFIC NORTHWEST AS IT DOES
SO...DIFFLUENT SOUTHWEST FLOW ALOFT IS EXPECTED TO DEVELOP ACROSS
THE CWA. THIS MAY LEAD TO CONVECTIVE SHOWERS ON WEDNESDAY...MAINLY
ACROSS THE SW ZONES. SOME OF THE SOUNDINGS IN THE NAM BUFKIT JUST
WEST OF THE CWA ARE SHOWING TOTAL TOTALS APPROACHING 50 AND LI
BECOMING NEGATIVE. DID NOT INSERT A MENTION OF THUNDER JUST YET DUE TO THE
FACT THAT THE PRIMARY FOCUS WAS ON THE CURRENT RAINFALL SITUATION
AND LAKE WIND POTENTIAL. HOWEVER...FUTURE SHIFTS MAY WANT TO
EVALUATE THE POTENTIAL FOR ANY CONVECTIVE INITIATION TOWARD THE
MIDDLE OF THE WEEK. MALIAWCO
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE EXTENDED FEATURES MORE SOUTHWEST FLOW THROUGH THE PERIOD. MOST
DAYS SLIGHT CHANCES OF THUNDERSTORMS SLIDING OFF THE CENTRAL
MONTANA MOUNTAINS INTO THE PLAINS FOR HIGHER POPS WEST AND LOW
POPS EAST. FOR THE WEEKEND THE UPPER LOW BREAKS A GOOD WAVE OFF
AND DRIVES IT THROUGH NORTHEAST MONTANA FOR A BETTER CHANCE OF
THUNDERSTORMS THEREFORE BUMPED UP POPS A TAD FOR THOSE PERIODS.
TEMPERATURES WILL HOLD IN NEAR NORMAL THROUGH THE PERIOD.
MODEL TRENDS ARE SHOWING LOWERING HEIGHTS ON THE GFS FOR NORTHEAST
MONTANA WHICH LEADS TO THE UPPER LOW MOVING TOWARDS THE EAST. IF
THE TREND CONTINUES THEN LIKELY POPS ARE A GOOD BET FOR THE
WEEKEND WITH ELEVATED CONFIDENCE. RMOP/ENSEMBLES ARE SHOWING THAT
ITS A GOOD BET THAT AT SOME POINT THIS UPCOMING WEEKEND FOR A
STRONG THUNDERSTORM EVENT ACROSS EASTERN MONTANA. PROTON
&&
.AVIATION...
MVFR FOR THE EASTERN AREAS INCLUDING KSDY AND KGDV THROUGH THE
PERIOD AS THEY ARE CLOSER TO THE LOW OVER SOUTHEASTERN NORTH
DAKOTA WHICH IS WRAPPING AROUND MOISTURE INTO THE LOWER YELLOWSTONE
RIVER VALLEY. THIS TREND LOOKS TO CONTINUE THROUGH THE PERIOD.
VFR FOR WESTERN AREAS INCLUDING KGGW AND KOLF THROUGH THE PERIOD
AS THE MVFR CEILING SHIELD LOOKS TO STAY JUST OFF TO THE EAST. FOR
NOW WILL STAY WITH VFR CEILINGS.
WIND WILL BE MORE OF AN ISSUE FOR THE EASTERN SITES WITH THE WINDS
STAYING UP ABOVE 20 KNOTS THROUGH THE END OF THE TAF PERIOD. PROTON
&&
.HYDROLOGY...
THE NEXT COUPLE OF DAYS WILL CONTINUE TO BE VERY WET AS NORTHEAST
MONTANA REMAINS UNDER THE INFLUENCE OF A LARGE UPPER TROUGH AND
VERTICALLY STACKED LOW PRESSURE SYSTEM SITUATED ACROSS THE
DAKOTAS. A LARGE AREA OF STRATIFORM RAIN WILL AFFECT ESPECIALLY EASTERN
AREAS OF THE FORECAST AREA. SOME LOCATIONS COULD PICK UP BETWEEN
ONE AND TWO INCHES OF RAINFALL BY TUESDAY MORNING...ESPECIALLY IN
EASTERN ROOSEVELT AND RICHLAND COUNTIES WHERE THE STEADIEST RAIN
IS EXPECTED.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO
ACCOMMODATE THIS AMOUNT OF MOISTURE. HOWEVER THERE IS SOME
CONCERN FOR RAPIDLY RISING STREAMS...FIELD FLOODING AND LOCALIZED
FLOODING IN TOWNS AS THE EVENT PERSISTS. SOME MINOR FLOODING MAY
BECOME AN ISSUE...ESPECIALLY FOR THE AREAS FROM WOLF POINT TO
CIRCLE AND EASTWARD INTO NORTH DAKOTA WHERE THE POTENTIAL FOR RAIN
IS THE HIGHEST.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...
GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 201002
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
402 AM MDT MON MAY 20 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
TODAY AND TONIGHT...A VERTICALLY STACKED LOW PRESSURE SYSTEM
SITUATED OVER THE DAKOTAS WILL CONTINUE TO SIT AND SPIN. AS IT
DOES...A SHIELD OF STRATIFORM RAIN WILL CONTINUE TO RETROGRADE
FROM EAST TO WEST THOUGH THE DAY...BEFORE CRASHING BACK TO THE
SOUTHEAST THIS AFTERNOON AND EVENING AS THE LOW BEGINS TO
TRANSLATE EASTWARD. DETERMINING THE MAXIMUM EXTENT OF THE BACK
EDGE OF THE RAINFALL SHIELD WILL CONTINUE TO BE THE MAIN FORECAST
CHALLENGE.
THE LATEST NAM HAD THE PRECIPITATION INITIALIZED A BIT FURTHER TO
THE EAST THAN RADAR OBSERVATIONS SHOWED. THUS...FEEL THE
PRECIPITATION SHIELD SHOULD MAKE IT A BIT FURTHER THAN THIS
SOLUTION IS SUGGESTING. THE 00Z ECMWF AND GFS HAVE A LITTLE BETTER
HANDLE ON IT. WILL ADMIT THAT THE HRRR HAS BEEN AN IMPRESSIVE
INFORMER AS IT CAUGHT ONTO THE IDEA THAT THE SHIELD WOULD STOP
RETROGRADING FOR A FEW HOURS OVERNIGHT BEFORE AGAIN PROCEEDING ITS
MARCH FURTHER WEST TOWARD MORNING AND THIS IS WHAT IS OCCURRING.
LENDING FURTHER SUPPORT TO THE GUIDANCE IS THE OBSERVATION OF
RECENT PRESSURE FALLS ACROSS THE CWA. PRESSURES ARE GENERALLY
FALLING BETWEEN 0.5 AND 1 MB PER HOUR FOR THE LAST FEW HOURS.
THEREFORE...WILL FEEL COMFORTABLE WITH A BLEND OF THE
ECMWF/GFS/HRRR MODEL SOLUTIONS FOR DETERMINING A BEST GUESS AS TO
WHERE THE BACK EDGE WILL REACH BEFORE IT BEGINS TO PUSH BACK TO
THE SOUTHEAST. THIS BRINGS IT TO A LINE FROM ABOUT OPHEIM...EXTENDING
SOUTH THROUGH JUST WEST OF GLASGOW...TO THE JORDAN AREA. TO THE
EAST OF THIS LINE...THERE IS A DECENT CHANCE AT A NICE WETTING
RAIN THROUGH TONIGHT. IN FACT...WOULD NOT BE SURPRISED IF SOME
AREAS SEE ONE TO TWO INCHES OF RAINFALL ACCUMULATION BY THE END OF
TONIGHT AND INCLUDED A MENTION OF HEAVY RAIN IN SOME OF THE
EASTERN ZONES THROUGH THE MORNING. TO THE WEST OF THIS LINE...RAIN
CHANCES WILL ONLY BE SHOWERY IN NATURE WITH A FEW HUNDREDTHS OF AN
INCH OF ACCUMULATION THE ABSOLUTE MOST THAT WOULD OCCUR. PRECISE
RAINFALL AMOUNTS WILL DEPEND UPON THE PRECISE LOCATION OF WHERE
THE BACK EDGE OF THIS RAIN SHIELD WINDS UP...AS WELL AS SOME FINER
MESOSCALE DETAILS THAT ARE DIFFICULT TO DETERMINE WITH MUCH
CONFIDENCE. TEMPERATURES ARE KEPT AROUND OR JUST BELOW SEASONAL
NORMALS DUE TO THE PRESENCE OF THE LINGERING UPPER TROUGH.
THE OTHER CONCERN TODAY WILL BE STRONG GUSTY WINDS DUE TO A SHARP
PRESSURE GRADIENT IN ASSOCIATION WITH THE SURFACE LOW ACROSS THE
DAKOTAS. AM EXPECTING THAT THE TIGHT PACKING OF THE ISOBARS COULD
SUPPORT NORTHERLY WINDS ON THE ORDER OF 20 TO 30 MPH WITH SOME
GUSTS EXCEEDING 40 MPH THIS AFTERNOON AND EVENING. WILL HOIST A
LAKE WIND ADVISORY FROM NOON UNTIL 9PM DUE TO THIS CONCERN. THIS
MAY ALSO LEAD TO WIND DRIVEN RAINS IN SOME LOCATIONS WHICH COULD
POSE AS HAZARDS TO TRAVELERS AND PEDESTRIANS ALIKE.
TONIGHT THROUGH WEDNESDAY...THE LOW PRESSURE SYSTEM OVER THE
DAKOTAS VERY GRADUALLY TRANSLATES EASTWARD...SO CONTINUED TO TREND
POPS DOWN AND HAVE PRECIPITATION SHUTTING OFF FROM WEST TO EAST.
WILL LEAVE ONLY A SLIGHT CHANCE OF RAIN SHOWERS IN THE EXTREME SE
ZONES BY LATE TUESDAY NIGHT. ON WEDNESDAY...ANOTHER UPPER TROUGH
WITH CLOSED LOW MOVES INTO THE PACIFIC NORTHWEST AS IT DOES
SO...DIFFLUENT SOUTHWEST FLOW ALOFT IS EXPECTED TO DEVELOP ACROSS
THE CWA. THIS MAY LEAD TO CONVECTIVE SHOWERS ON WEDNESDAY...MAINLY
ACROSS THE SW ZONES. SOME OF THE SOUNDINGS IN THE NAM BUFKIT JUST
WEST OF THE CWA ARE SHOWING TOTAL TOTALS APPROACHING 50 AND LI
BECOMING NEGATIVE. DID NOT INSERT A MENTION OF THUNDER JUST YET DUE TO THE
FACT THAT THE PRIMARY FOCUS WAS ON THE CURRENT RAINFALL SITUATION
AND LAKE WIND POTENTIAL. HOWEVER...FUTURE SHIFTS MAY WANT TO
EVALUATE THE POTENTIAL FOR ANY CONVECTIVE INITIATION TOWARD THE
MIDDLE OF THE WEEK. MALIAWCO
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE EXTENDED FEATURES MORE SOUTHWEST FLOW THROUGH THE PERIOD. MOST
DAYS SLIGHT CHANCES OF THUNDERSTORMS SLIDING OFF THE CENTRAL
MONTANA MOUNTAINS INTO THE PLAINS FOR HIGHER POPS WEST AND LOW
POPS EAST. FOR THE WEEKEND THE UPPER LOW BREAKS A GOOD WAVE OFF
AND DRIVES IT THROUGH NORTHEAST MONTANA FOR A BETTER CHANCE OF
THUNDERSTORMS THEREFORE BUMPED UP POPS A TAD FOR THOSE PERIODS.
TEMPERATURES WILL HOLD IN NEAR NORMAL THROUGH THE PERIOD.
MODEL TRENDS ARE SHOWING LOWERING HEIGHTS ON THE GFS FOR NORTHEAST
MONTANA WHICH LEADS TO THE UPPER LOW MOVING TOWARDS THE EAST. IF
THE TREND CONTINUES THEN LIKELY POPS ARE A GOOD BET FOR THE
WEEKEND WITH ELEVATED CONFIDENCE. RMOP/ENSEMBLES ARE SHOWING THAT
ITS A GOOD BET THAT AT SOME POINT THIS UPCOMING WEEKEND FOR A
STRONG THUNDERSTORM EVENT ACROSS EASTERN MONTANA. PROTON
&&
.AVIATION...
MVFR FOR THE EASTERN AREAS INCLUDING KSDY AND KGDV THROUGH THE
PERIOD AS THEY ARE CLOSER TO THE LOW OVER SOUTHEASTERN NORTH
DAKOTA WHICH IS WRAPPING AROUND MOISTURE INTO THE LOWER YELLOWSTONE
RIVER VALLEY. THIS TREND LOOKS TO CONTINUE THROUGH THE PERIOD.
VFR FOR WESTERN AREAS INCLUDING KGGW AND KOLF THROUGH THE PERIOD
AS THE MVFR CEILING SHIELD LOOKS TO STAY JUST OFF TO THE EAST. FOR
NOW WILL STAY WITH VFR CEILINGS.
WIND WILL BE MORE OF AN ISSUE FOR THE EASTERN SITES WITH THE WINDS
STAYING UP ABOVE 20 KNOTS THROUGH THE END OF THE TAF PERIOD. PROTON
&&
.HYDROLOGY...
THE NEXT COUPLE OF DAYS WILL CONTINUE TO BE VERY WET AS NORTHEAST
MONTANA REMAINS UNDER THE INFLUENCE OF A LARGE UPPER TROUGH AND
VERTICALLY STACKED LOW PRESSURE SYSTEM SITUATED ACROSS THE
DAKOTAS. A LARGE AREA OF STRATIFORM RAIN WILL AFFECT ESPECIALLY EASTERN
AREAS OF THE FORECAST AREA. SOME LOCATIONS COULD PICK UP BETWEEN
ONE AND TWO INCHES OF RAINFALL BY TUESDAY MORNING...ESPECIALLY IN
EASTERN ROOSEVELT AND RICHLAND COUNTIES WHERE THE STEADIEST RAIN
IS EXPECTED.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO
ACCOMMODATE THIS AMOUNT OF MOISTURE. HOWEVER THERE IS SOME
CONCERN FOR RAPIDLY RISING STREAMS...FIELD FLOODING AND LOCALIZED
FLOODING IN TOWNS AS THE EVENT PERSISTS. SOME MINOR FLOODING MAY
BECOME AN ISSUE...ESPECIALLY FOR THE AREAS FROM WOLF POINT TO
CIRCLE AND EASTWARD INTO NORTH DAKOTA WHERE THE POTENTIAL FOR RAIN
IS THE HIGHEST.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...
GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 200311
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
911 PM MDT SUN MAY 19 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
UPDATE...
CONVECTIVE SHOWER ACTIVITY IS BEGINNING TO FADE AS IT PUSHES OUT
OF PHILLIPS AND PETROLEUM COUNTIES. WILL GO AHEAD AND REDUCE POPS
A BIT TO ACCOUNT FOR THIS. A SURFACE LOW PRESSURE IS SENDING A
RETROGRADING SHIELD OF STRATIFORM RAIN INTO THE CWA FROM EAST TO
WEST AS IT BECOMES VERTICALLY STACKED OVER THE DAKOTAS. MAIN
FORECAST CHALLENGE WILL BE FINAL RAINFALL AMOUNTS...AND THE FINAL
WESTERN EXTENT OF THE RAIN AS IT PUSHES INTO THE FORECAST REGION.
THE LATEST NAM AND ECMWF APPEARS TO BE TOO SLOW WITH THE
RETROGRADING RAIN SHIELD. THE HRRR SOLUTION SEEMS TO BE A BIT TOO
BULLISH WITH PRECIPITATION IN SOME OF THE CENTRAL ZONES. THE GFS
IS FAIRLY CLOSE IN LINE WITH THE INITIAL LOCATION OF THE WESTERN
EDGE OF THE STRATIFORM RAIN AND THEREFORE HAVE PLACED A LITTLE
MORE WEIGHT ON THAT SOLUTION. BELIEVE THAT OVERNIGHT THE BACK
EXTENT OF THE RAIN WILL REACH A LINE EXTENDING FROM ABOUT JUST
EAST OF OPHEIM...THROUGH GLASGOW...AND INTO WESTERN GARFIELD
COUNTY. WILL TAKE A LOOK AT THE OOZ MODEL SUITE AS IT CONTINUES TO
COME IN AND MAKE ANY NEEDED ADJUSTMENTS FOR THE MORNING PACKAGE.
THE OTHER CONSIDERATION WILL BE SURFACE WIND SPEEDS TOMORROW WITH
THE PRESENCE OF A PRETTY TIGHT PRESSURE GRADIENT OVER ESPECIALLY
THE EASTERN HALF OF THE CWA. NOT SURE IF A LAKE WIND ADVISORY WILL
BE NECESSARY AS IT LOOKS FAIRLY MARGINAL. MALIAWCO
PREVIOUS SHORT TERM DISCUSSION...
THE LOW PRESSURE CENTERS ARE CLOSING OFF AND BEGINNING TO STACK
OVER THE DAKOTAS. THE FOCUS OF PRECIPITATION IS WHERE THE INVERTED
SURFACE TROUGH NUDGES INTO THE WESTERN DAKOTAS AND EASTERN
COUNTIES OF NORTHEAST MONTANA. A BIT OF DRY SLOTTING INITIALLY
THROUGH THE CENTRAL COUNTIES OF NORTHEAST MONTANA...THEN THE
WESTERN COUNTIES AFTER MIDNIGHT WILL DIMINISH CHANCES THERE OF ANY
MEANINGFUL PRECIPITATION. EXPECT WIND TO PICK UP...MAINLY IN THE
EAST...AS THE SURFACE LOW RETROGRADES BACK TOWARDS OUR CWA.
MONDAY...THE WRAP-AROUND PRECIPITATION CONTINUES ON THE HEAVY
SIDE IN THE MORNING...BUT FINALLY AS THE LOW MOVES FARTHER EAST
THE INVERTED SURFACE TROUGH IS PULLED AWAY AND RAIN INTENSITY
DIMINISHES DURING THE AFTERNOON...BUT SHOULD CONTINUE MONDAY
NIGHT IN THE EAST. THE LOW MOVING AWAY WILL ALSO LIGHTEN THE WIND
IN THE WEST. BUT WIND IN THE EAST WILL BECOME STRONG FROM THE
NORTH DUE TO THE NEARNESS OF THE SURFACE LOW AND WIND ALOFT THAT
LINES UP. THIS WIND COULD EDGE FAR ENOUGH WEST FOR THE NEED OF A
WIND ADVISORY FOR THE EASTERN END OF FORT PECK LAKE. WILL TURN
THAT OVER TO THE OVERNIGHT SHIFT FOR ANOTHER LOOK. THERE COULD BE
SOME CLEARING IN THE NORTHWEST LATE THIS AFTERNOON AND EVENING.
TUESDAY...THE INFLUENCE OF THE LOW WILL BE TENACIOUS IN ITS REACH
INTO THE EASTERN COUNTIES OF NORTHEAST MONTANA QPF WILL LIGHT BUT
LOW OVERCAST CONTINUES. FOR THE WESTERN COUNTIES CONDITIONS WILL
BE INFLUENCED BY WEAK RIDGING BETWEEN THE DEPARTING LOW AND THE
NEXT STRONG LOW BUMPING UP AGAINST THE WASHINGTON/OREGON COAST.
TEMPERATURE DURING THE SHORT TERM WILL BE MILD AND VERY NEAR
NORMAL FOR THIS TIME OF YEAR. TEMPERATURES WILL TEND TO PUT A LID
ON THUNDERSTORM ACTIVITY...BUT WILL LEAVE ISOLATED TS IN DURING
THIS EVENINGS IN THE WEST WHERE THERE ARE A FEW GENERAL
THUNDERSTORMS. SCT
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LOW OVER THE NORTHERN PLAINS EXPECTED TO SLIDE EAST BY THE
BEGINNING OF THE EXTENDED PERIOD...TO BE REPLACED BY A NARROW
UPPER RIDGE AS ANOTHER CLOSED LOW SETTLES INTO THE PACIFIC
NORTHWEST. NORTHEAST MONTANA WILL BE IN THE BOUNDARY AREA WHERE
THE SOUTHWEST FLOW AROUND THE BASE OF THE LOW MEETS THE UPPER
RIDGE. MAIN CHANCE OF RAIN WILL BE ACROSS THE WESTERN ZONES
THROUGH MIDWEEK THEN SPREAD EAST INTO THE WEEKEND AS THE MODELS
BEGIN TO OPEN UP THE LOW. EBERT
PREVIOUS LONG TERM DISCUSSION...THE EXTENDED PERIOD CONTINUES WITH
UPPER LOWS TO OUR WEST AND EAST AND CONFUSED FLOW OVER NORTHEAST
MONTANA. THIS WILL CONTINUE UNTIL FRIDAY WHEN THE UPPER LOW IN THE
PACIFIC NORTHWEST SHIFTS CLOSER TO NORTHEAST MONTANA. THIS WILL
ENHANCE THE POSSIBILITY OF THUNDERSTORMS OVER THE WEEKEND.
TEMPERATURES WILL CONTINUE AROUND NORMAL WITH HIGHS HOVERING
AROUND 70 AND LOWS IN THE UPPER 40S TO LOWER 50S THROUGH THE PERIOD.
MODEL TRENDS SHOW A FAIRLY SMOOTH RUN TO RUN PERFORMANCE WHICH
ASSISTS WITH A HIGH CONFIDENCE. DID NOT GO TOO HIGH FOR POPS OVER
THE UPCOMING WEEKEND SINCE THERE IS A HINT OF RETROGRESSION
STARTING TO SHOW UP WITH FALLING HEIGHTS IN MOST ENSEMBLES OVER
THE NORTHEAST PACIFIC. THIS COULD LEAD TO THE UPPER LOW SINKING
FURTHER SOUTH AND WEST KEEPING NORTHEAST MONTANA DRIER. OVERALL
ENSEMBLES ARE FAIRLY GOOD SINCE WE ARE IN A CLIMATOLOGICAL NORMAL
PATTERN. RMOP ARE FAIRLY GOOD WITH THE LARGE SCALE FEATURES FOR
THE EXTENDED PERIOD. THEREFORE MODERATE TO GOOD CONFIDENCE IN THE
PERIOD FROM TUESDAY NIGHT THROUGH FRIDAY WITH SOME LOWER
CONFIDENCE IN THE WEEKEND PATTERN. PROTON
&&
.AVIATION...
VFR BECOMING MVFR OVERNIGHT AS RAIN RETURNS TO THE REGION FROM THE
EAST...SLIGHTLY WORSE CONDITIONS AT KSDY WITH HEAVIER RAIN
EXPECTED. CIGS WILL BE CLOSE TO IFR AT TIMES LATE TONIGHT/EARLY
MONDAY AT ESPECIALLY KSDY AND KGDV. GUSTY NORTH WINDS ALSO
EXPECTED TO PERSIST THROUGH MONDAY MORNING. JAMBA
&&
.HYDROLOGY...
THE NEXT COUPLE OF DAYS WILL BE RATHER WET AS AN UPPER-LEVEL
TROUGH AFFECTS THE REGION. SEVERAL DISTURBANCES ASSOCIATED WITH THIS
TROUGH WILL PASS THROUGH WHICH WILL KEEP CHANCES FOR RAIN THROUGH
TUESDAY. MODEL GUIDANCE DEPICTS HIGH AMOUNTS OF MOISTURE WITH THIS
SYSTEM. AT THIS POINT THE ENVIRONMENT LOOKS FAVORABLE FOR SLOW-
MOVING STORMS WITH HIGHER PRECIPITATION IN LOCALIZED AREAS.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO
ACCOMMODATE THIS AMOUNT OF MOISTURE. HOWEVER THERE IS SOME
CONCERN FOR RAPIDLY RISING STREAMS...FIELD FLOODING AND LOCALIZED
FLOODING IN TOWNS AS THE EVENT PERSISTS. SOME MINOR FLOODING MAY
BECOME AN ISSUE...ESPECIALLY FOR THE AREAS FROM WOLF POINT TO
CIRCLE AND EASTWARD INTO NORTH DAKOTA WHERE THE POTENTIAL FOR RAIN
IS HIGHER.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 192030
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
230 PM MDT SUN MAY 19 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
THE LOW PRESSURE CENTERS ARE CLOSING OFF AND BEGINNING TO STACK
OVER THE DAKOTAS. THE FOCUS OF PRECIPITATION IS WHERE THE
INVERTED SURFACE TROUGH NUDGES INTO THE WESTERN DAKOTAS AND
EASTERN COUNTIES OF NORTHEAST MONTANA. A BIT OF DRY SLOTTING
INITIALLY THROUGH THE CENTRAL COUNTIES OF NORTHEAST MONTANA...THEN
THE WESTERN COUNTIES AFTER MIDNIGHT WILL DIMINISH CHANCES THERE OF
ANY MEANINGFUL PRECIPITATION. EXPECT WIND TO PICK UP...MAINLY IN
THE EAST...AS THE SURFACE LOW RETROGRADES BACK TOWARDS OUR CWA.
MONDAY...THE WRAP-AROUND PRECIPITATION CONTINUES ON THE HEAVY
SIDE IN THE MORNING...BUT FINALLY AS THE LOW MOVES FARTHER EAST
THE INVERTED SURFACE TROUGH IS PULLED AWAY AND RAIN INTENSITY
DIMINISHES DURING THE AFTERNOON...BUT SHOULD CONTINUE MONDAY
NIGHT IN THE EAST. THE LOW MOVING AWAY WILL ALSO LIGHTEN THE WIND
IN THE WEST. BUT WIND IN THE EAST WILL BECOME STRONG FROM THE
NORTH DUE TO THE NEARNESS OF THE SURFACE LOW AND WIND ALOFT THAT
LINES UP. THIS WIND COULD EDGE FAR ENOUGH WEST FOR THE NEED OF A
WIND ADVISORY FOR THE EASTERN END OF FORT PECK LAKE. WILL TURN
THAT OVER TO THE OVERNIGHT SHIFT FOR ANOTHER LOOK. THERE COULD BE
SOME CLEARING IN THE NORTHWEST LATE THIS AFTERNOON AND EVENING.
TUESDAY...THE INFLUENCE OF THE LOW WILL BE TENACIOUS IN ITS REACH
INTO THE EASTERN COUNTIES OF NORTHEAST MONTANA QPF WILL LIGHT BUT
LOW OVERCAST CONTINUES. FOR THE WESTERN COUNTIES CONDITIONS WILL
BE INFLUENCED BY WEAK RIDGING BETWEEN THE DEPARTING LOW AND THE
NEXT STRONG LOW BUMPING UP AGAINST THE WASHINGTON/OREGON COAST.
TEMPERATURE DURING THE SHORT TERM WILL BE MILD AND VERY NEAR
NORMAL FOR THIS TIME OF YEAR. TEMPERATURES WILL TEND TO PUT A LID
ON THUNDERSTORM ACTIVITY...BUT WILL LEAVE ISOLATED TS IN DURING
THIS EVENINGS IN THE WEST WHERE THERE ARE A FEW GENERAL
THUNDERSTORMS. SCT
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LOW OVER THE NORTHERN PLAINS EXPECTED TO SLIDE EAST BY THE
BEGINNING OF THE EXTENDED PERIOD...TO BE REPLACED BY A NARROW
UPPER RIDGE AS ANOTHER CLOSED LOW SETTLES INTO THE PACIFIC
NORTHWEST. NORTHEAST MONTANA WILL BE IN THE BOUNDARY AREA WHERE
THE SOUTHWEST FLOW AROUND THE BASE OF THE LOW MEETS THE UPPER
RIDGE. MAIN CHANCE OF RAIN WILL BE ACROSS THE WESTERN ZONES
THROUGH MIDWEEK THEN SPREAD EAST INTO THE WEEKEND AS THE MODELS
BEGIN TO OPEN UP THE LOW. EBERT
PREVIOUS LONG TERM DISCUSSION...THE EXTENDED PERIOD CONTINUES WITH
UPPER LOWS TO OUR WEST AND EAST AND CONFUSED FLOW OVER NORTHEAST
MONTANA. THIS WILL CONTINUE UNTIL FRIDAY WHEN THE UPPER LOW IN THE
PACIFIC NORTHWEST SHIFTS CLOSER TO NORTHEAST MONTANA. THIS WILL
ENHANCE THE POSSIBILITY OF THUNDERSTORMS OVER THE WEEKEND.
TEMPERATURES WILL CONTINUE AROUND NORMAL WITH HIGHS HOVERING
AROUND 70 AND LOWS IN THE UPPER 40S TO LOWER 50S THROUGH THE PERIOD.
MODEL TRENDS SHOW A FAIRLY SMOOTH RUN TO RUN PERFORMANCE WHICH
ASSISTS WITH A HIGH CONFIDENCE. DID NOT GO TOO HIGH FOR POPS OVER
THE UPCOMING WEEKEND SINCE THERE IS A HINT OF RETROGRESSION
STARTING TO SHOW UP WITH FALLING HEIGHTS IN MOST ENSEMBLES OVER
THE NORTHEAST PACIFIC. THIS COULD LEAD TO THE UPPER LOW SINKING
FURTHER SOUTH AND WEST KEEPING NORTHEAST MONTANA DRIER. OVERALL
ENSEMBLES ARE FAIRLY GOOD SINCE WE ARE IN A CLIMATOLOGICAL NORMAL
PATTERN. RMOP ARE FAIRLY GOOD WITH THE LARGE SCALE FEATURES FOR
THE EXTENDED PERIOD. THEREFORE MODERATE TO GOOD CONFIDENCE IN THE
PERIOD FROM TUESDAY NIGHT THROUGH FRIDAY WITH SOME LOWER
CONFIDENCE IN THE WEEKEND PATTERN. PROTON
&&
.AVIATION...
VFR BECOMING MVFR OVERNIGHT AS RAIN RETURNS TO THE REGION. GUSTY
NORTH WINDS ALSO EXPECTED TO PERSIST THROUGH MONDAY MORNING.
&&
.HYDROLOGY...
THE NEXT COUPLE OF DAYS WILL BE RATHER WET AS AN UPPER-LEVEL
TROUGH AFFECTS THE REGION. SEVERAL DISTURBANCES ASSOCIATED WITH THIS
TROUGH WILL PASS THROUGH WHICH WILL KEEP CHANCES FOR RAIN THROUGH
TUESDAY. MODEL GUIDANCE DEPICTS HIGH AMOUNTS OF MOISTURE WITH THIS
SYSTEM. AT THIS POINT THE ENVIRONMENT LOOKS FAVORABLE FOR SLOW-
MOVING STORMS WITH HIGHER PRECIPITATION IN LOCALIZED AREAS.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO
ACCOMMODATE THIS AMOUNT OF MOISTURE. HOWEVER THERE IS SOME
CONCERN FOR RAPIDLY RISING STREAMS...FIELD FLOODING AND LOCALIZED
FLOODING IN TOWNS AS THE EVENT PERSISTS. SOME MINOR FLOODING MAY
BECOME AN ISSUE...ESPECIALLY FOR THE AREAS FROM WOLF POINT TO
CIRCLE AND EASTWARD INTO NORTH DAKOTA WHERE THE POTENTIAL FOR RAIN
IS HIGHER.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 191520 AAA
AFDGGW
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GLASGOW MT
920 AM MDT SUN MAY 19 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
THE LOW PRESSURE CENTERS ARE CLOSING OFF AND BEGINNING TO STACK
OVER THE WESTERN DAKOTAS WHERE THE FOCUS OF PRECIPITATION IS THIS
MORNING. A BIT OF DRY SLOTTING THROUGH THE CENTRAL COUNTIES OF
NORTHEAST MONTANA PROMPTED SOME ADJUSTMENTS TO POPS/QPF AND WX FOR
TODAY. EXPECT WIND TO PICK UP AS THE SURFACE LOW RETROGRADES BACK
TOWARDS OUR CWA. AS IT DOES THE INVERTED SURFACE TROUGH NUDGES
INTO NEMONT BRINGING HEAVIER RAIN AND SOME THUNDERSTORMS BY LATE
AFTERNOON. ADJUSTED WIND BASED ON OBSERVATIONS AND THE LATEST
GUIDANCE. TEMPERATURES LOOK GOOD SO NO ADJUSTMENTS THERE. SCT
PREVIOUS DISCUSSION...
TODAY THROUGH MONDAY NIGHT...UPPER LEVEL TROUGH WILL CONTINUE TO
PROVIDE UNSETTLED WEATHER CONDITIONS FOR NE MT. A SURFACE LOW
PRESSURE SYSTEM WILL CONTINUE TO SIT AND SPIN AS IT BECOMES
VERTICALLY STACKED OVER EASTERN SOUTH DAKOTA BY MONDAY. THIS LOW
PRESSURE WILL CONTINUE TO PUMP EASTERLY SURFACE FLOW INTO THE CWA
WHICH WITH COMBINED WITH LOBES OF UPPER LEVEL SHORTWAVE ENERGY
SWIRLING AROUND THE TROUGH...WILL HELP PROVIDE THE SUPPORT FOR A
CONTINUATION OF VERY STEADY RAIN SHOWERS. LOOKING AT NAM BUFR
FORECAST SOUNDINGS...DO NOTE THAT LI IS NEAR 0 IN SOME LOCATIONS
DURING SUNDAY AFTERNOON WITH TOTAL TOTALS HOVERING AROUND 50.
GIVEN THE CONVECTIVE NATURE OF THE PULSES OF SHOWER ACTIVITY THAT
HAVE OCCURRED THE PAST COUPLE OF DAYS HOWEVER...AM NOT COMPLETELY
SOLD ON THE IDEA THAT THUNDER WILL NOT AT ALL BE A POSSIBILITY.
WITH THE STEADY RAINS...DO FEEL EMBEDDED THUNDER IS A POSSIBILITY
AND SO KEPT IN A SLIGHT MENTION OF IT. SOUNDINGS ARE ALSO SHOWING
AN INCH OR MORE PRECIPITABLE WATER THROUGH THIS PERIOD AND SO
THERE IS CERTAINLY PLENTY OF MOISTURE IN THE VERTICAL TO WORK
WITH.
MODEL GUIDANCE HAS BEEN FAIRLY CONSISTENT WITH THE STEADY
RAINS AFFECTING MUCH OF THE CWA THROUGH MONDAY NIGHT...BUT
PREFERRED THE ECMWF AND THE HRRR SOLUTIONS GIVEN EXCELLENT RUN TO
RUN CONTINUITY. WILL EXPECT THE HEAVIEST RAINFALL AMOUNTS IN THE
SOUTHEASTERN ZONES CLOSER TO THE SURFACE LOW...BUT ISOLATED HIGHER
RAINFALL TOTALS MAY OCCUR WHERE THUNDER AND/OR THE STEADIEST
RAINFALL DOES OCCUR. THAT WILL LARGELY DEPEND UPON MESOSCALE
DETAILS THAT ARE COMPLEX AND DIFFICULT TO PINPOINT AT THIS TIME.
CERTAINLY THERE WILL LIKELY BE A WIDESPREAD WETTING RAIN ACROSS
THE CWA THROUGH MONDAY NIGHT...BUT ISOLATED LOCATIONS MAY PICK UP
AN ADDITIONAL ONE TO TWO INCHES OF RAINFALL.
TUESDAY...THE RAIN SLOWLY EXITS THE FORECAST REGION FROM WEST TO
EAST. HAVE DROPPED OFF POPS ACCORDINGLY DURING THE DAY ON TUESDAY
AND ESPECIALLY TUESDAY NIGHT. WITH LITTLE CHANGE IN THE FORECAST
850MB TEMPERATURES...WILL NOT EXPECT MUCH IN THE WAY OF SWINGS.
EXPECTING SEASONAL CONDITIONS THROUGH THE ENTIRE SHORT TERM
PERIOD...OR PERHAPS SLIGHTLY BELOW AVERAGE WITH THE LARGE TROUGH
IN PLACE. MALIAWCO
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
THE EXTENDED PERIOD CONTINUES WITH UPPER LOWS TO OUR WEST AND EAST
AND CONFUSED FLOW OVER NORTHEAST MONTANA. THIS WILL CONTINUE UNTIL
FRIDAY WHEN THE UPPER LOW IN THE PACIFIC NORTHWEST SHIFTS CLOSER
TO NORTHEAST MONTANA. THIS WILL ENHANCE THE POSSIBILITY OF
THUNDERSTORMS OVER THE WEEKEND.
TEMPERATURES WILL CONTINUE AROUND NORMAL WITH HIGHS HOVERING
AROUND 70 AND LOWS IN THE UPPER 40S TO LOWER 50S THROUGH THE PERIOD.
MODEL TRENDS SHOW A FAIRLY SMOOTH RUN TO RUN PERFORMANCE WHICH
ASSISTS WITH A HIGH CONFIDENCE. DID NOT GO TOO HIGH FOR POPS OVER
THE UPCOMING WEEKEND SINCE THERE IS A HINT OF RETROGRESSION
STARTING TO SHOW UP WITH FALLING HEIGHTS IN MOST ENSEMBLES OVER
THE NORTHEAST PACIFIC. THIS COULD LEAD TO THE UPPER LOW SINKING
FURTHER SOUTH AND WEST KEEPING NORTHEAST MONTANA DRIER. OVERALL
ENSEMBLES ARE FAIRLY GOOD SINCE WE ARE IN A CLIMATOLOGICAL NORMAL
PATTERN. RMOP ARE FAIRLY GOOD WITH THE LARGE SCALE FEATURES FOR
THE EXTENDED PERIOD. THEREFORE MODERATE TO GOOD CONFIDENCE IN THE
PERIOD FROM TUESDAY NIGHT THROUGH FRIDAY WITH SOME LOWER
CONFIDENCE IN THE WEEKEND PATTERN. PROTON
&&
.AVIATION...
MVFR. MODELS HAVE BEEN A LITTLE LOW ON CEILING HEIGHTS AT ALL
LOCATIONS FOR PAST 48 HOURS AND LOOK TO CONTINUE THE TREND FOR THE
NEXT 24 HOURS. WILL MAINTAIN MVFR AT MOST LOCATIONS WITH LOW VFR
FOR GLASGOW THROUGH THE PERIOD. COOLER TEMPERATURES ALOFT WILL
CONTINUE THE SHOWERY CONDITIONS THROUGH THE PERIOD. PROTON
&&
.HYDROLOGY...
THE NEXT FEW DAYS WILL BE RATHER WET AS AN UPPER-LEVEL TROUGH
AFFECTS THE AREA. SEVERAL DISTURBANCES ASSOCIATED WITH THIS
TROUGH WILL PASS THROUGH WHICH WILL KEEP CHANCES FOR RAIN WITH
SOME THUNDERSTORMS THROUGH EARLY NEXT WEEK. MODEL GUIDANCE DEPICTS
HIGH AMOUNTS OF MOISTURE WITH THIS SYSTEM. AT THIS POINT THE
ENVIRONMENT LOOKS FAVORABLE FOR SLOW-MOVING STORMS WITH HIGHER
PRECIPITATION IN LOCALIZED AREAS.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO
ACCOMMODATE THIS AMOUNT OF MOISTURE...AT LEAST EARLY ON IN THE
EVENT. THERE IS SOME CONCERN FOR RAPIDLY RISING STREAMS...FIELD
FLOODING AND LOCALIZED FLOODING IN TOWNS AS THE EVENT PERSISTS.
SOME MINOR FLOODING MAY BECOME AN ISSUE... ESPECIALLY FOR THE
AREAS FROM GLASGOW TO CIRCLE AND EASTWARD INTO NORTH DAKOTA WHERE
THE POTENTIAL FOR STRONGER THUNDERSTORMS IS HIGHER.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 190952
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
352 AM MDT SUN MAY 19 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
TODAY THROUGH MONDAY NIGHT...UPPER LEVEL TROUGH WILL CONTINUE TO
PROVIDE UNSETTLED WEATHER CONDITIONS FOR NE MT. A SURFACE LOW
PRESSURE SYSTEM WILL CONTINUE TO SIT AND SPIN AS IT BECOMES
VERTICALLY STACKED OVER EASTERN SOUTH DAKOTA BY MONDAY. THIS LOW
PRESSURE WILL CONTINUE TO PUMP EASTERLY SURFACE FLOW INTO THE CWA
WHICH WITH COMBINED WITH LOBES OF UPPER LEVEL SHORTWAVE ENERGY
SWIRLING AROUND THE TROUGH...WILL HELP PROVIDE THE SUPPORT FOR A
CONTINUATION OF VERY STEADY RAIN SHOWERS. LOOKING AT NAM BUFR
FORECAST SOUNDINGS...DO NOTE THAT LI IS NEAR 0 IN SOME LOCATIONS
DURING SUNDAY AFTERNOON WITH TOTAL TOTALS HOVERING AROUND 50.
GIVEN THE CONVECTIVE NATURE OF THE PULSES OF SHOWER ACTIVITY THAT
HAVE OCCURRED THE PAST COUPLE OF DAYS HOWEVER...AM NOT COMPLETELY
SOLD ON THE IDEA THAT THUNDER WILL NOT AT ALL BE A POSSIBILITY.
WITH THE STEADY RAINS...DO FEEL EMBEDDED THUNDER IS A POSSIBILITY
AND SO KEPT IN A SLIGHT MENTION OF IT. SOUNDINGS ARE ALSO SHOWING
AN INCH OR MORE PRECIPITABLE WATER THROUGH THIS PERIOD AND SO
THERE IS CERTAINLY PLENTY OF MOISTURE IN THE VERTICAL TO WORK
WITH.
MODEL GUIDANCE HAS BEEN FAIRLY CONSISTENT WITH THE STEADY
RAINS AFFECTING MUCH OF THE CWA THROUGH MONDAY NIGHT...BUT
PREFERRED THE ECMWF AND THE HRRR SOLUTIONS GIVEN EXCELLENT RUN TO
RUN CONTINUITY. WILL EXPECT THE HEAVIEST RAINFALL AMOUNTS IN THE
SOUTHEASTERN ZONES CLOSER TO THE SURFACE LOW...BUT ISOLATED HIGHER
RAINFALL TOTALS MAY OCCUR WHERE THUNDER AND/OR THE STEADIEST
RAINFALL DOES OCCUR. THAT WILL LARGELY DEPEND UPON MESOSCALE
DETAILS THAT ARE COMPLEX AND DIFFICULT TO PINPOINT AT THIS TIME.
CERTAINLY THERE WILL LIKELY BE A WIDESPREAD WETTING RAIN ACROSS
THE CWA THROUGH MONDAY NIGHT...BUT ISOLATED LOCATIONS MAY PICK UP
AN ADDITIONAL ONE TO TWO INCHES OF RAINFALL.
TUESDAY...THE RAIN SLOWLY EXITS THE FORECAST REGION FROM WEST TO
EAST. HAVE DROPPED OFF POPS ACCORDINGLY DURING THE DAY ON TUESDAY
AND ESPECIALLY TUESDAY NIGHT. WITH LITTLE CHANGE IN THE FORECAST
850MB TEMPERATURES...WILL NOT EXPECT MUCH IN THE WAY OF SWINGS.
EXPECTING SEASONAL CONDITIONS THROUGH THE ENTIRE SHORT TERM
PERIOD...OR PERHAPS SLIGHTLY BELOW AVERAGE WITH THE LARGE TROUGH
IN PLACE. MALIAWCO
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
THE EXTENDED PERIOD CONTINUES WITH UPPER LOWS TO OUR WEST AND EAST
AND CONFUSED FLOW OVER NORTHEAST MONTANA. THIS WILL CONTINUE UNTIL
FRIDAY WHEN THE UPPER LOW IN THE PACIFIC NORTHWEST SHIFTS CLOSER
TO NORTHEAST MONTANA. THIS WILL ENHANCE THE POSSIBILITY OF
THUNDERSTORMS OVER THE WEEKEND.
TEMPERATURES WILL CONTINUE AROUND NORMAL WITH HIGHS HOVERING
AROUND 70 AND LOWS IN THE UPPER 40S TO LOWER 50S THROUGH THE PERIOD.
MODEL TRENDS SHOW A FAIRLY SMOOTH RUN TO RUN PERFORMANCE WHICH
ASSISTS WITH A HIGH CONFIDENCE. DID NOT GO TOO HIGH FOR POPS OVER
THE UPCOMING WEEKEND SINCE THERE IS A HINT OF RETROGRESSION
STARTING TO SHOW UP WITH FALLING HEIGHTS IN MOST ENSEMBLES OVER
THE NORTHEAST PACIFIC. THIS COULD LEAD TO THE UPPER LOW SINKING
FURTHER SOUTH AND WEST KEEPING NORTHEAST MONTANA DRIER. OVERALL
ENSEMBLES ARE FAIRLY GOOD SINCE WE ARE IN A CLIMATOLOGICAL NORMAL
PATTERN. RMOP ARE FAIRLY GOOD WITH THE LARGE SCALE FEATURES FOR
THE EXTENDED PERIOD. THEREFORE MODERATE TO GOOD CONFIDENCE IN THE
PERIOD FROM TUESDAY NIGHT THROUGH FRIDAY WITH SOME LOWER
CONFIDENCE IN THE WEEKEND PATTERN. PROTON
&&
.AVIATION...
MVFR. MODELS HAVE BEEN A LITTLE LOW ON CEILING HEIGHTS AT ALL
LOCATIONS FOR PAST 48 HOURS AND LOOK TO CONTINUE THE TREND FOR THE
NEXT 24 HOURS. WILL MAINTAIN MVFR AT MOST LOCATIONS WITH LOW VFR
FOR GLASGOW THROUGH THE PERIOD. COOLER TEMPERATURES ALOFT WILL
CONTINUE THE SHOWERY CONDITIONS THROUGH THE PERIOD. PROTON
&&
.HYDROLOGY...
THE NEXT FEW DAYS WILL BE RATHER WET AS AN UPPER-LEVEL TROUGH
AFFECTS THE AREA. SEVERAL DISTURBANCES ASSOCIATED WITH THIS TROUGH
WILL PASS THROUGH WHICH WILL KEEP CHANCES FOR RAIN WITH SOME
THUNDERSTORMS THROUGH EARLY NEXT WEEK. MODEL GUIDANCE DEPICTS HIGH
AMOUNTS OF MOISTURE WITH THIS SYSTEM. AT THIS POINT THE
ENVIRONMENT LOOKS FAVORABLE FOR SLOW-MOVING STORMS WITH HIGHER
PRECIPITATION IN LOCALIZED AREAS.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO ACCOMMODATE
THIS AMOUNT OF MOISTURE... AT LEAST EARLY ON IN THE EVENT. THERE IS
SOME CONCERN FOR RAPIDLY RISING STREAMS...FIELD FLOODING AND
LOCALIZED FLOODING IN TOWNS AS THE EVENT PERSISTS. SOME MINOR
FLOODING MAY BECOME AN ISSUE... ESPECIALLY FOR THE AREAS FROM
GLASGOW TO CIRLE AND EASTWARD INTO NORTH DAKOTA WHERE THE POTENTIAL
FOR STRONGER THUNDERSTORMS IS HIGHER.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 190331
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
931 PM MDT SAT MAY 18 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
UPDATE...SHOWERS AND THUNDERSTORMS ARE CONTINUING TO AFFECT THE
CWA THIS EVENING. A FAIRLY CONCENTRATED AREA OF SHOWERS AND
THUNDERSTORMS PRODUCING HEAVY RAINFALL HAVE BEEN DRIFTING VERY
SLOWLY SOUTHEASTWARD ACROSS SOUTHERN MCCONE COUNTY. THIS PROMPTED
THE ISSUANCE OF A FLOOD ADVISORY THROUGH 11PM FOR POOR POOR DRAINAGE
AREAS NEAR HIGHWAYS 200 AND 253 NEAR BROCKWAY. IN FACT...A COUPLE OF
CALLS HAVE COME IN THIS EVENING DESCRIBING SOME FLOODING ON
HIGHWAY 253 NEAR BROCKWAY.
LATEST HRRR GUIDANCE HAS SHOWER AND THUNDERSTORM ACTIVITY
DIMINISHING SOME AS IT LIFTS NORTHWARD...BUT ALSO DEPICTS SOME
REDEVELOPMENT ACROSS SOME OF THE WESTERN PORTIONS OF THE CWA. THIS
HAS SOME SUPPORT FROM THE LATEST NAM AND THE 12Z ECMWF AS WELL SO
INCREASED POPS OVERNIGHT IN THESE AREAS. BUFKIT SOUNDINGS SHOWS
TOTAL TOTALS AROUND 50 AND LI BETWEEN 0 AND -1 FOR A LOT OF THE
CWA AROUND 06Z AND SO INCLUDED A MENTION OF THUNDER FOR THE REST
OF THE OVERNIGHT AS WELL. MALIAWCO
PREVIOUS SHORT TERM DISCUSSION...
A LARGE TROUGH HAS DUG IN OVER THE SOUTH WEST CONUS WITH A RIDGE
OVER WESTERN CANADA. VARIABLE IMPULSES OF ENERGY MOVING UP FROM
THE DOWNSTREAM PART OF THE SOUTHERN TROUGH WILL SUPPORT CONTINUED
PRECIPITATION THROUGH MONDAY AFTERNOON. RAINFALL IS ALSO SUPPORTED
BY A SURFACE LOW SOUTHEAST OF MONTANA THAT IS DRAWING LOW LEVEL
MOISTURE INTO THE AREA.
SYSTEM CONTINUES TO STRENGTHEN AND GRADUALLY MOVE EASTWARD...WITH
THE EFFECTS EXITING NORTHEAST MONTANA MONDAY NIGHT. ON
MONDAY...MOST OF THE MODELS HAVE MOST OF THE PRECIPITATION TO THE
SOUTHEAST PART OF THE CWA...BUT WITH POTENTIALLY HIGHER AMOUNTS
THAN EARLIER IN THE FORECAST. SOUNDINGS ARE VERY SATURATED WITH
AROUND AN INCH OF PRECIPITABLE WATER..LEADING TO THE FORECAST OF
MOSTLY RAIN SHOWERS. SOME INSTABILITY IN THE SOUNDINGS WILL LEAD
TO SOME LIMITED THUNDERSTORM ACTIVITY. THUNDERSTORMS ARE LIMITED
BY THE LACK OF CAP...WHICH WILL NOT ALLOW MUCH BUILD-UP OF
CONVECTIVE ENERGY. WINDS WILL PICK A LITTLE FROM THE NORTH ON
SUNDAY AS THE SURFACE LOW TIGHTENS...HOWEVER...THEY SHOULD STAY
BELOW 20KTS...WITH LOCALLY HIGHER GUSTS POSSIBLE IN OUTFLOW AREAS. MARTIN
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
THE ONLY CHANGES IN THE SHORT TERM LOOK TO BE STRONGER WINDS
THURSDAY AND THE POSSIBILITY FOR A SEVERE EVENT OR TWO AT THE END
OF THE PERIOD.
THE GFS WANTS TO RAMP UP WINDS QUITE A BIT THURSDAY AFTERNOON WITH
850 WINDS OVER THE CWA APPROACHING 50 KNOTS AS A MID LEVEL HIGH
OVER THE MINNESOTA AND ONTARIO REGION BATTLES WITH THE APPROACHING
PACIFIC NORTHWEST LOW. THE ECMWF HAS A BIT LESS AMPLIFIED GRADIENT
AND THUS A THINNER BAND OF STRONG 850 WINDS OVER THE CWA...BUT HAS
A SIMILAR UPPER PATTERN AS GFS. WENT CLOSER TO THE ECMWF SOLUTION
AS THE GFS TENDS TO HAVE WINDS A BIT HIGH OVER THE AREA.
AS THE UPPER LOW APPROACHES FOR THE WEEKEND...LOBES OF SHORTWAVE
ENERGY MAY CONTINUE TO BRING CHANCES FOR THUNDERSTORM DEVELOPMENT.
SATURDAY AFTERNOON HAS THE GFS AND ECMWF PUTTING OUT OVER 2000
J/KG OF CAPE OVER PARTS OF THE AREA...SO THERE WILL BE PLENTY OF
INSTABILITY OVER THE REGION. SUNDAY AFTERNOON AND EVENING SHOWS ROUGHLY
THE SAME SCENARIO...AND EVEN DIPS INTO MONDAY AS THE LOW SLOWLY
PROGRESSES NORTHWARD OFF TO OUR WEST AND NORTHWEST. THIS WILL
PROVIDE BROAD SOUTHWEST FLOW ALOFT FOR THE WEEKEND...WHICH SHOULD
GIVE ENOUGH UPPER LEVEL SUPPORT WITH DIFLUENT FLOW COMBINED WITH
LOBES OF SHORTWAVE ENERGY OFF THE MAIN FLOW...ESPECIALLY FOR
SATURDAY. FOR NOW...THE GFS HAS A WARM FRONT PASS THROUGH THE CWA
FRIDAY...AND THE ECMWF HAS ONE PASS SATURDAY. MORE MODEL AGREEMENT
ON TIMING WILL SHOW IF WE GET OUR FIRST SIGNIFICANT ROUND OF
STORMS THIS SEASON NEXT WEEKEND. BARNWELL
PREVIOUS LONG TERM DISCUSSION...THE EXTENDED FORECAST BEGINS
MONDAY NIGHT WITH AN UPPER LOW EXITING INTO THE UPPER MISSISSIPPI
RIVER VALLEY AND WEAK RIDGING BUILDING INTO NORTHEASTERN MONTANA.
BY WEDNESDAY MORNING ANOTHER UPPER LOW MOVES IN OVER THE PACIFIC
NORTHWEST SETTING UP DI-FLUENT SOUTHWEST FLOW ALOFT OVER THE AREA
THROUGH THE END OF THE EXTENDED.
THIS WILL CONTINUE THE COOLISH TEMPERATURES DURING THE DAY AND
NEAR NORMAL TEMPERATURES AT NIGHT. PRECIPITATION CHANCES SHOULD
RANGE SLIGHTLY ABOVE NORMAL... HOWEVER PIN POINTING ANY BETTER
DAYS THAN OTHERS WILL BE VERY HARD.
ENSEMBLES OF THE GFS AND EC SHOW HIGH CONFIDENCE IN AN UPPER LOW
OVER THE PACIFIC NORTHWEST...HOWEVER DO HAVE TROUBLE KEEPING THE
DAY TO DAY PLACEMENT OF THE UPPER LOW THE SAME. RMOP IS PRETTY
GOOD FOR UPPER LOWS OVER THE PACIFIC NORTHWEST. MODERATE TO HIGH
CONFIDENCE ON THE PATTERN. HOWEVER THE PATTERN IS MORE SHOWERY IN
NATURE NOT ALLOWING FOR THE CONFIDENCE TO DOUBLE OF CLIMO POPS AT
THIS TIME. PROTON
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO DETERIORATE TO MVFR AND POSSIBLY IFR
FOR KGDV AND KSDY LATER TONIGHT AS AN AREA OF SHOWERS AND
THUNDERSTORMS MOVE NORTHEAST INTO THESE AREAS. BETTER CONDITIONS
ARE EXPECTED FOR KGGW AND KOLF WHERE LIGHTER RAINS ARE EXPECTED
TONIGHT.
SINCE KOLF ASOS IS NOT TRANSMITTING..WE HAVE TAGGED THE TAF WITH
AMD NOT SKED. JAMBA
&&
.HYDROLOGY...
THE NEXT FEW DAYS WILL BE RATHER WET AS AN UPPER-LEVEL TROUGH
AFFECTS THE AREA. SEVERAL DISTURBANCES ASSOCIATED WITH THIS TROUGH
WILL PASS THROUGH WHICH WILL KEEP CHANCES FOR RAIN WITH SOME
THUNDERSTORMS THROUGH EARLY NEXT WEEK. MODEL GUIDANCE DEPICTS HIGH
AMOUNTS OF MOISTURE WITH THIS SYSTEM. AT THIS POINT THE
ENVIRONMENT LOOKS FAVORABLE FOR SLOW-MOVING STORMS WITH HIGHER
PRECIPITATION IN LOCALIZED AREAS.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO ACCOMMODATE
THIS AMOUNT OF MOISTURE... AT LEAST EARLY ON IN THE EVENT. THERE IS
SOME CONCERN FOR RAPIDLY RISING STREAMS...FIELD FLOODING AND
LOCALIZED FLOODING IN TOWNS AS THE EVENT PERSISTS. SOME MINOR
FLOODING MAY BECOME AN ISSUE... ESPECIALLY FOR THE AREAS FROM
GLASGOW TO CIRLE AND EASTWARD INTO NORTH DAKOTA WHERE THE POTENTIAL
FOR STRONGER THUNDERSTORMS IS HIGHER.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 182102
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
302 PM MDT SAT MAY 18 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
A LARGE TROUGH HAS DUG IN OVER THE SOUTH WEST CONUS WITH A RIDGE
OVER WESTERN CANADA. VARIABLE IMPULSES OF ENERGY MOVING UP FROM
THE DOWNSTREAM PART OF THE SOUTHERN TROUGH WILL SUPPORT CONTINUED
PRECIPITATION THROUGH MONDAY AFTERNOON. RAINFALL IS ALSO SUPPORTED
BY A SURFACE LOW SOUTHEAST OF MONTANA THAT IS DRAWING LOW LEVEL
MOISTURE INTO THE AREA.
SYSTEM CONTINUES TO STRENGTHEN AND GRADUALLY MOVE EASTWARD...WITH
THE EFFECTS EXITING NORTHEAST MONTANA MONDAY NIGHT. ON
MONDAY...MOST OF THE MODELS HAVE MOST OF THE PRECIPITATION TO THE
SOUTHEAST PART OF THE CWA...BUT WITH POTENTIALLY HIGHER AMOUNTS
THAN EARLIER IN THE FORECAST. SOUNDINGS ARE VERY SATURATED WITH
AROUND AN INCH OF PRECIPITABLE WATER..LEADING TO THE FORECAST OF
MOSTLY RAIN SHOWERS. SOME INSTABILITY IN THE SOUNDINGS WILL LEAD
TO SOME LIMITED THUNDERSTORM ACTIVITY. THUNDERSTORMS ARE LIMITED
BY THE LACK OF CAP...WHICH WILL NOT ALLOW MUCH BUILD-UP OF
CONVECTIVE ENERGY. WINDS WILL PICK A LITTLE FROM THE NORTH ON
SUNDAY AS THE SURFACE LOW TIGHTENS...HOWEVER...THEY SHOULD STAY
BELOW 20KTS...WITH LOCALLY HIGHER GUSTS POSSIBLE IN OUTFLOW AREAS. MARTIN
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
THE ONLY CHANGES IN THE SHORT TERM LOOK TO BE STRONGER WINDS
THURSDAY AND THE POSSIBILITY FOR A SEVERE EVENT OR TWO AT THE END
OF THE PERIOD.
THE GFS WANTS TO RAMP UP WINDS QUITE A BIT THURSDAY AFTERNOON WITH
850 WINDS OVER THE CWA APPROACHING 50 KNOTS AS A MID LEVEL HIGH
OVER THE MINNESOTA AND ONTARIO REGION BATTLES WITH THE APPROACHING
PACIFIC NORTHWEST LOW. THE ECMWF HAS A BIT LESS AMPLIFIED GRADIENT
AND THUS A THINNER BAND OF STRONG 850 WINDS OVER THE CWA...BUT HAS
A SIMILAR UPPER PATTERN AS GFS. WENT CLOSER TO THE ECMWF SOLUTION
AS THE GFS TENDS TO HAVE WINDS A BIT HIGH OVER THE AREA.
AS THE UPPER LOW APPROACHES FOR THE WEEKEND...LOBES OF SHORTWAVE
ENERGY MAY CONTINUE TO BRING CHANCES FOR THUNDERSTORM DEVELOPMENT.
SATURDAY AFTERNOON HAS THE GFS AND ECMWF PUTTING OUT OVER 2000
J/KG OF CAPE OVER PARTS OF THE AREA...SO THERE WILL BE PLENTY OF
INSTABILITY OVER THE REGION. SUNDAY AFTERNOON AND EVENING SHOWS ROUGHLY
THE SAME SCENARIO...AND EVEN DIPS INTO MONDAY AS THE LOW SLOWLY
PROGRESSES NORTHWARD OFF TO OUR WEST AND NORTHWEST. THIS WILL
PROVIDE BROAD SOUTHWEST FLOW ALOFT FOR THE WEEKEND...WHICH SHOULD
GIVE ENOUGH UPPER LEVEL SUPPORT WITH DIFLUENT FLOW COMBINED WITH
LOBES OF SHORTWAVE ENERGY OFF THE MAIN FLOW...ESPECIALLY FOR
SATURDAY. FOR NOW...THE GFS HAS A WARM FRONT PASS THROUGH THE CWA
FRIDAY...AND THE ECMWF HAS ONE PASS SATURDAY. MORE MODEL AGREEMENT
ON TIMING WILL SHOW IF WE GET OUR FIRST SIGNIFICANT ROUND OF
STORMS THIS SEASON NEXT WEEKEND. BARNWELL
PREVIOUS LONG TERM DISCUSSION...THE EXTENDED FORECAST BEGINS
MONDAY NIGHT WITH AN UPPER LOW EXITING INTO THE UPPER MISSISSIPPI
RIVER VALLEY AND WEAK RIDGING BUILDING INTO NORTHEASTERN MONTANA.
BY WEDNESDAY MORNING ANOTHER UPPER LOW MOVES IN OVER THE PACIFIC
NORTHWEST SETTING UP DI-FLUENT SOUTHWEST FLOW ALOFT OVER THE AREA
THROUGH THE END OF THE EXTENDED.
THIS WILL CONTINUE THE COOLISH TEMPERATURES DURING THE DAY AND
NEAR NORMAL TEMPERATURES AT NIGHT. PRECIPITATION CHANCES SHOULD
RANGE SLIGHTLY ABOVE NORMAL... HOWEVER PIN POINTING ANY BETTER
DAYS THAN OTHERS WILL BE VERY HARD.
ENSEMBLES OF THE GFS AND EC SHOW HIGH CONFIDENCE IN AN UPPER LOW
OVER THE PACIFIC NORTHWEST...HOWEVER DO HAVE TROUBLE KEEPING THE
DAY TO DAY PLACEMENT OF THE UPPER LOW THE SAME. RMOP IS PRETTY
GOOD FOR UPPER LOWS OVER THE PACIFIC NORTHWEST. MODERATE TO HIGH
CONFIDENCE ON THE PATTERN. HOWEVER THE PATTERN IS MORE SHOWERY IN
NATURE NOT ALLOWING FOR THE CONFIDENCE TO DOUBLE OF CLIMO POPS AT
THIS TIME. PROTON
&&
.AVIATION...
A MIX OF VFR WITH PERIODS OF MVFR CAN BE EXPECTED THROUGH THE
PERIOD AT ALL TERMINALS. SOUTHWEST FLOW ALOFT AND MOIST EAST TO
SOUTHEAST FLOW WILL KEEP SKIES BROKEN TO OVERCAST. CEILINGS WILL
BE TRICKY... GUIDANCE HAS A SPLIT WITH ONE GOING FOR SOLID
MVFR...THE OTHER SOLID VFR. WILL GO WITH THE PREDOMINATE OF VFR
AND PERIODS OF MVFR MAINLY FOR MORNING LOWER CEILINGS AND ANY
AFTERNOON CBS THAT FORM. LIGHT RAIN SHOWERS ARE EXPECTED ON AND
OFF THROUGHOUT THE ENTIRE TAF PERIOD.
KOLF ASOS IS NOT TRANSMITTING THE OBSERVATIONS FOR US TO SEE THEM
ONLINE AND INSTEAD WE ARE HAVING TO CALL EVERY HOUR. THEREFORE THE
TAF IS AMD NOT SKED.
PROTON/FRANSEN
&&
.HYDROLOGY...
THE NEXT FEW DAYS WILL BE RATHER WET AS AN UPPER-LEVEL TROUGH
AFFECTS THE AREA. SEVERAL DISTURBANCES ASSOCIATED WITH THIS TROUGH
WILL PASS THROUGH WHICH WILL KEEP CHANCES FOR RAIN WITH SOME
THUNDERSTORMS THROUGH EARLY NEXT WEEK. MODEL GUIDANCE DEPICTS HIGH
AMOUNTS OF MOISTURE WITH THIS SYSTEM. AT THIS POINT THE
ENVIRONMENT LOOKS FAVORABLE FOR SLOW-MOVING STORMS WITH HIGHER
PRECIPITATION IN LOCALIZED AREAS.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO ACCOMMODATE
THIS AMOUNT OF MOISTURE... AT LEAST EARLY ON IN THE EVENT. THERE IS
SOME CONCERN FOR RAPIDLY RISING STREAMS...FIELD FLOODING AND
LOCALIZED FLOODING IN TOWNS AS THE EVENT PERSISTS. SOME MINOR
FLOODING MAY BECOME AN ISSUE... ESPECIALLY FOR THE AREAS FROM
GLASGOW TO CIRLE AND EASTWARD INTO NORTH DAKOTA WHERE THE POTENTIAL
FOR STRONGER THUNDERSTORMS IS HIGHER.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
000
FXUS65 KGGW 181540
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
940 AM MDT SAT MAY 18 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
UPDATED FORECAST TO ACCOUNT FOR RADAR PPT TRENDS AND SHORT TERM
MODEL FORECASTS. MORNING SOUNDING IS SATURATED WITH PRECIPITABLE
WATER OF ABOUT AN INCH...WHICH IS CLOSE TO THE 99TH PERCENTILE FOR
THIS TIME OF YEAR. DEEP WET AND UNCAPPED SOUNDING IS
CHARACTERISTIC OF A PERSISTENT RAIN EVENT...WITH SOME THUNDER
POSSIBLE. HOWEVER...HAVE DEEMPHASIZED THE IMPACT FROM
THUNDERSTORMS AS RAIN IS THE MAIN IMPACT. DISORGANIZED UPPER FLOW
WITH WEAK TO MODEST DYNAMIC FORCING SUGGESTS PERIODS OF RAIN OFF
AND ON FOR THE NEXT 2 OR 3 DAYS WITH SPECIFIC LOCATIONS RECEIVING
THE MOST RAIN DIFFICULT TO PIN DOWN. MODELS DO DIFFER ON WHEN RAIN
WILL TAPER OFF WITH THE GFS MODEL MORE RAPIDLY PROGRESSING THE
SYSTEM EASTWARD...HOWEVER...TEND TO FAVOR THE EC AND NAM MODELS
WHICH HAVE HAD GREATER RUN TO RUN CONSISTENCY. MARTIN
PREVIOUS DISCUSSION...
TODAY THROUGH MONDAY...MAIN CONCERN WILL BE THE CONTINUATION OF
WET WEATHER ACROSS NORTHEAST MONTANA. CURRENT RADAR OBSERVATIONS
EARLY THIS MORNING ARE SHOWING A RATHER EXPANSIVE AREA OF SHOWER
ACTIVITY ACROSS THE CWA. SOME 40-50 DBZ REFLECTIVITY HAS BEEN
OCCURRING FROM TIME TO TIME IN VERY ISOLATED LOCATIONS AND SO
CANNOT RULE OUT A RUMBLE OF THUNDER THIS MORNING.
MODELS ARE IN EXCELLENT AGREEMENT WITH THE OVERALL SYNOPTIC
PATTERN KEEPING IN AN UPPER LEVEL TROUGH PERSISTING ACROSS THE CWA
WHICH WILL PROVIDE A CONTINUATION OF UNSETTLED WEATHER CONDITIONS.
HOWEVER...THERE ARE NOTABLE DIFFERENCES FROM THE MODELS IN THE DETAILS
AND HANDLING OF MESOSCALE CONVECTION THAT DEVELOPS. THE GFS IN
PARTICULAR HAS NOT BEEN PERFORMING WELL IN THE PLACEMENT OF QPF
WITH RECENT RAIN SHOWER ACTIVITY AND THEREFORE HAVE DISCOUNTED IT
FOR THE SHORT TERM FORECAST PERIOD. THE 00Z ECMWF AND THE LATEST
HRRR HAVE SHOWN TO HAVE A PRETTY GOOD HANDLE ON THE OVERALL
SITUATION AND LEANED WITH A COMPROMISE OF THEIR SOLUTIONS IN LARGE
PART FOR THE FORECAST. IN A NUTSHELL...UPPER LEVEL SHORTWAVE
FEATURES WILL PROPAGATE THROUGH SOUTHWEST FLOW ALOFT WHICH ALONG
WITH UPPER LEVEL DIFFLUENCE WILL HELP FORCE VERTICAL ASCENT. A
SURFACE LOW PRESSURE WILL ALSO SIT AND SPIN ACROSS THE DAKOTAS
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK WHICH WILL CONTINUE
TO PROVIDE MOIST EASTERLY FLOW INTO NORTHEAST MONTANA. GIVEN THESE
CIRCUMSTANCES...FEEL VERY CONFIDENT IN WIDESPREAD MEASURABLE
RAINFALL ACCUMULATIONS.
THE CHALLENGE WITH THIS FORECAST WILL BE DETERMINING WHERE THE
HEAVIEST AMOUNTS OF RAINFALL WILL OCCUR...WHICH WILL LARGELY
DEPEND UPON MESOSCALE DETAILS THAT ARE DIFFICULT TO PINPOINT WITH
MUCH CONFIDENCE AT THIS TIME. AREAS WITH HEAVIEST RAINFALL MAY
CERTAINLY PICK UP OVER AN INCH OF RAINFALL...IF NOT MORE...THROUGH
EARLY NEXT WEEK. GIVEN THESE ARGUMENTS...WILL GO WITH CATEGORICAL
POPS IN MOST PLACES THROUGH SUNDAY NIGHT AND TAPER TO LIKELY POPS
ON MONDAY AS THE UPPER TROUGH BEGINS TO TRANSLATE EASTWARD AND THE
SURFACE LOW EXITS THE DAKOTAS AND HEADS FOR SW MN AND NW IA. NAM
BUFR SOUNDINGS CONTINUE TO INDICATE LI READINGS AROUND 0 OR
SLIGHTLY NEGATIVE ACROSS PARTS OF THE CWA AT TIMES GOING INTO
TONIGHT...AND INDICATE SMALL AMOUNTS OF CAPE AND SOME INSTABILITY.
DECIDED TO KEEP A SLIGHT MENTION FOR THUNDER IN THE GRIDS GIVEN
THESE ARGUMENTS. NO LARGE SWINGS IN TEMPERATURES ARE EXPECTED
THROUGH THE SHORT TERM SINCE THE OVERALL PATTERN WILL REMAIN
RATHER STATIC. THEREFORE WILL EXPECT SEASONAL HIGHS AND LOWS
THROUGH EARLY NEXT WEEK. MALIAWCO
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
THE EXTENDED FORECAST BEGINS MONDAY NIGHT WITH AN UPPER LOW
EXITING INTO THE UPPER MISSISSIPPI RIVER VALLEY AND WEAK RIDGING
BUILDING INTO NORTHEASTERN MONTANA.
BY WEDNESDAY MORNING ANOTHER UPPER LOW MOVES IN OVER THE PACIFIC
NORTHWEST SETTING UP DI-FLUENT SOUTHWEST FLOW ALOFT OVER THE AREA
THROUGH THE END OF THE EXTENDED.
THIS WILL CONTINUE THE COOLISH TEMPERATURES DURING THE DAY AND
NEAR NORMAL TEMPERATURES AT NIGHT. PRECIPITATION CHANCES SHOULD
RANGE SLIGHTLY ABOVE NORMAL... HOWEVER PIN POINTING ANY BETTER
DAYS THAN OTHERS WILL BE VERY HARD.
ENSEMBLES OF THE GFS AND EC SHOW HIGH CONFIDENCE IN AN UPPER LOW
OVER THE PACIFIC NORTHWEST...HOWEVER DO HAVE TROUBLE KEEPING THE
DAY TO DAY PLACEMENT OF THE UPPER LOW THE SAME. RMOP IS PRETTY
GOOD FOR UPPER LOWS OVER THE PACIFIC NORTHWEST. MODERATE TO HIGH
CONFIDENCE ON THE PATTERN. HOWEVER THE PATTERN IS MORE SHOWERY IN
NATURE NOT ALLOWING FOR THE CONFIDENCE TO DOUBLE OF CLIMO POPS AT
THIS TIME. PROTON
&&
.AVIATION...
A MIX OF VFR WITH PERIODS OF MVFR CAN BE EXPECTED THROUGH THE
PERIOD AT ALL TERMINALS. SOUTHWEST FLOW ALOFT AND MOIST EAST TO
SOUTHEAST FLOW WILL KEEP SKIES BROKEN TO OVERCAST. CEILINGS WILL
BE TRICKY... GUIDANCE HAS A SPLIT WITH ONE GOING FOR SOLID
MVFR...THE OTHER SOLID VFR. WILL GO WITH THE PREDOMINATE OF VFR
AND PERIODS OF MVFR MAINLY FOR MORNING LOWER CEILINGS AND ANY
AFTERNOON CBS THAT FORM. LIGHT RAIN SHOWERS ARE EXPECTED ON AND
OFF THROUGHOUT THE ENTIRE TAF PERIOD.
KOLF ASOS IS NOT TRANSMITTING THE OBSERVATIONS FOR US TO SEE THEM
ONLINE AND INSTEAD WE ARE HAVING TO CALL EVERY HOUR. THEREFORE THE
TAF IS AMD NOT SKED.
PROTON/FRANSEN
&&
.HYDROLOGY...
THE NEXT FEW DAYS WILL BE RATHER WET AS AN UPPER-LEVEL TROUGH
AFFECTS THE AREA. SEVERAL DISTURBANCES ASSOCIATED WITH THIS TROUGH
WILL PASS THROUGH WHICH WILL KEEP CHANCES FOR RAIN WITH SOME
THUNDERSTORMS THROUGH EARLY NEXT WEEK. MODEL GUIDANCE DEPICTS HIGH
AMOUNTS OF MOISTURE WITH THIS SYSTEM. AT THIS POINT THE
ENVIRONMENT LOOKS FAVORABLE FOR SLOW- MOVING STORMS WITH HIGHER
PRECIPITATION IN LOCALIZED AREAS.
MOST OF THE BASINS IN NORTHEAST MONTANA WILL BE ABLE TO ACCOMMODATE
THIS AMOUNT OF MOISTURE... AT LEAST EARLY ON IN THE EVENT. THERE IS
SOME CONCERN FOR RAPIDLY RISING STREAMS AND LOCALIZED URBAN
FLOODING AS THE EVENT PERSISTS. SOME FLOODING MAY BECOME AN
ISSUE... ESPECIALLY FOR THE EASTERN AND SOUTHERN COUNTIES WHERE
THE POTENTIAL FOR STRONGER THUNDERSTORMS IS HIGHER.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
| 
