000
FXUS65 KBYZ 182100
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
300 PM MDT TUE JUN 18 2013
.SHORT TERM...VALID FOR WED AND THU...
CONVECTION WAS OCCURRING OVER SOUTHERN PARTS OF THE AREA PER
RADAR IMAGERY THIS AFTERNOON. LATEST RAP ANALYSIS SHOWED SURFACE
CAPES OF 1500-2500 J/KG OVER SE MT. ELSEWHERE...CAPES WERE IN THE
700 TO 2000 J/KG RANGE...PRETTY VARIABLE ACROSS THE FORECAST AREA.
SHEAR WAS GENERALLY WEAK...HOWEVER VALUES WERE 30 TO 35 KT OVER SE
MT...SO BEST CHANCES OF ANY STRONG TO SEVERE STORMS WILL BE OVER
THE SE. WILL CONTINUE TO MENTION SMALL HAIL/GUSTY WINDS ACROSS THE
AREA DUE TO THE CAPES AND INVERTED-V SOUNDINGS. HAD POPS ACROSS
THE AREA THIS EVENING...THEN ACTIVITY SHOULD DISSIPATE AFTER
MIDNIGHT MDT WITH LOSS OF HEATING.
JET ENERGY WILL ROTATE AROUND THE UPPER LOW OVER THE PACIFIC
NW...CAUSING IT TO PROGRESS E WITH TIME. WILL HAVE INCREASING
Q-VECTOR CONVERGENCE OVER THE AREA STARTING ON WED...AS SHORTWAVES
CONTINUE MOVING INTO THE REGION. UPPER DIFLUENCE WILL CONTINUE TO
CONTRIBUTE TO LIFT ON WED. BOTH THE GFS AND WRF HAD LARGE CAPES
2000-3000 J/KG OVER THE FAR EASTERN AND NORTHERN PARTS OF THE
AREA WED AND WED EVENING...AS WELL AS INCREASING SHEAR OVER THE
AREA FROM W TO E. HOWEVER...DRY AIR OVER THE FOUR CORNERS REGION
THIS AFTERNOON WILL ADVECT N INTO THE FORECAST AREA ON
WED...KEEPING THE E DRY THROUGH THE DAY. WILL KEEP A CHANCE OF
THUNDERSTORMS OVER THE NW HALF OF THE REGION FROM KBIL N AND W...AND
WILL CONTINUE TO MENTION POSSIBLE SEVERE OVER THE N. COLD FRONT
MOVES THROUGH WED NIGHT BRINGING A CHANCE OF THUNDERSTORMS TO MOST
OF THE AREA.
UPPER LOW WILL ROTATE OVER ID THU AND THU NIGHT. CAPES WILL BE VERY
LOW ON THU. HAD LOW POPS ACROSS THE AREA. A SECONDARY COLD FRONT
WITH FRONTOGENESIS WILL MOVE THROUGH THE REGION THU
NIGHT...BRINGING A BETTER CHANCE OF PRECIPITATION.
WILL HAVE A WARM NIGHT TONIGHT AS 850 MB THERMAL RIDGE MOVES INTO
THE AREA AND LOW-LEVEL JET STRENGTHENS OVER THE E. WED WILL BE HOT
WITH 700 MB TEMPERATURES AROUND +14 DEGREES C AHEAD OF THE COLD
FRONT. ARTHUR
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
PAC NW UPPER LOW WILL KICK SLOWLY THROUGH THE REGION FRI/SAT...AND
ALL MODELS HAVE TRENDED SIMILARLY WITH REGARD TO STRENGTH AND
TIMING OF THIS FEATURE. WITH CONFIDENCE HAVE RAISED POPS ACROSS
THE REGION ON THESE DAYS. ACTIVITY IN THE WEST SHOULD BE NON-
SEVERE THOUGH WITH LOW WET BULB TEMPS SOME SMALL HAIL IS POSSIBLE
WITH ANY STRONGER CELLS. GFS SHOWS DEEPER MOISTURE AND INSTABILITY
MAY SURGE FROM THE DAKOTAS INTO OUR EAST AHEAD OF THE UPPER
LOW...SO CANNOT RULE OUT THE POTENTIAL FOR SEVERE STORMS IN OUR
EAST ON THESE DAYS...ALONG WITH HEAVY RAIN. SYSTEM WILL EXIT TO
OUR EAST EITHER SATURDAY NIGHT OR EARLY SUNDAY. TEMPS FRIDAY AND
SATURDAY WILL COOL TO SLIGHTLY BELOW NORMAL.
DRIER CONDITIONS SHOULD EMERGE BY SUNDAY IN OUR WEST...WITH A
PERIOD OF DRY WX PERHAPS EXTENDING INTO MONDAY UNDER SHORTWAVE
RIDGING. MODELS DIVERGE A BIT IN THE HANDLING OF THE PACIFIC FLOW
HERE. WILL ADVERTISE A DRY PERIOD SUNDAY INTO MONDAY...THEN SLIGHT
POPS MONDAY AFTERNOON THROUGH TUESDAY AS WE MAY BE IMPACTED BY
PACIFIC SHORTWAVE ENERGY BY THEN. TEMPS SHOULD RETURN BACK TO A
LITTLE ABOVE NORMAL BY DAYS 6/7.
LOOKING FURTHER AHEAD...LATEST GFS/ECMWF SHOW STRONGER RIDGING
WITH NEAR 590DAM HEIGHTS BY WED/THU OF NEXT WEEK. WILL NEED TO
KEEP WATCH OF THIS TREND.
JKL
&&
.AVIATION...
A WEAK DISTURBANCE WILL BRING ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING...WITH GREATEST COVERAGE
NEAR THE MTNS AND FOOTHILLS...POSSIBLY IMPACTING KLVM AND KSHR AT
TIMES. VFR WILL PREVAIL BUT LOCAL MVFR IS POSSIBLE IN ANY STRONGER
STORMS...AND MOUNTAINS WILL BE OCCASIONALLY OBSCURED. THIS
ACTIVITY WILL DIMINISH AFTER SUNSET. ON WEDNESDAY...AN APPROACHING
COLD FRONT WILL BRING ANOTHER CHANCE OF THUNDERSTORMS ALONG WITH
GUSTIER WINDS. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 060/089 052/077 052/072 052/069 051/078 054/082 056/082
22/T 22/T 33/T 34/T 41/B 12/T 22/T
LVM 050/084 043/072 041/069 042/067 046/079 046/082 049/081
33/T 23/T 33/T 34/T 40/B 02/T 22/T
HDN 059/091 053/078 052/074 050/072 050/078 052/082 052/083
21/U 22/T 32/T 34/T 41/B 12/T 22/T
MLS 061/096 058/081 055/076 056/076 055/080 056/083 057/083
21/N 22/T 44/T 34/T 43/T 22/T 22/T
4BQ 061/095 054/081 055/076 054/075 053/079 054/084 055/084
31/N 22/T 44/T 34/T 42/T 12/T 22/T
BHK 057/090 057/080 054/076 055/074 054/076 054/080 057/082
31/N 22/T 36/T 54/T 43/T 22/T 22/T
SHR 054/090 048/078 050/073 048/073 047/076 049/081 050/082
31/U 22/T 32/T 23/T 31/B 12/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 181543
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
943 AM MDT TUE JUN 18 2013
.UPDATE...
JUST A FEW POP ADJUSTMENTS FOR THE AFTERNOON TO GO CLOSER TO THE
SREF SOLUTION WHICH WAS HANDLING THE MORNING PRECIPITATION IN THE
NE BIG HORNS WELL. UPPER LOW OFF THE PACIFIC NW COAST WILL EJECT
SHORTWAVE ENERGY INTO THE FORECAST AREA THIS AFTERNOON IN SW FLOW.
PRECIPITABLE WATERS WILL BE AROUND /0.75/ INCHES TODAY WITH CAPES
1000 J/KG OR LESS. SOUNDINGS HAD A BIT OF AN INVERTED-V
APPEARANCE WHICH WOULD SUPPORT GUSTY WINDS WITH ANY THUNDERSTORMS.
THE CAPES WILL SUPPORT SMALL HAIL...SO CONTINUED THE MENTION OF
GUSTY WINDS/SMALL HAIL IN THE FORECAST. SHEAR VALUES WERE NOT
IMPRESSIVE THIS AFTERNOON. THE BEST SHEAR WILL BE OVER THE EASTERN
ZONES AROUND 00Z WED...BUT WILL STILL NOT BE VERY STRONG.
TEMPERATURE FORECAST WAS IN GOOD SHAPE AND REFLECTED MIXDOWN
VALUES. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND WED...
YESTERDAY AFTERNOON SAW SOME ISOLATED SHOWERS AND THUNDERSTORMS
OVER MOUNTAIN LOCATIONS...BUT THOSE FAILED TO MOVE OFF INTO THE
LOWER ELEVATIONS. ENVIRONMENTAL CONDITIONS TODAY WILL BE SIMILAR
TO YESTERDAY. DEW POINTS ARE EXPECTED TO BE IN THE MID 40S TO LOWER
50S ESPECIALLY FOR CENTRAL AND WESTERN ZONES. THIS LOW-LEVEL
MOISTURE IS MARGINALLY ENOUGH TO CONSIDER THE THREAT OF
THUNDERSTORMS MOVING OFF THE MOUNTAINS AND INTO THE PLAINS ACROSS
WESTERN ZONES. HOWEVER...THE AMOUNT OF MOISTURE IS ALSO LIMITING
IN THE SENSE THAT LFCS ARE VERY HIGH...ON THE ORDER OF 10K FEET.
ALTHOUGH TEMPERATURES ARE EXPECTED TO RISE TO THE UPPER 80S TO
NEAR 90...WHICH IS CLOSE TO THE CONVECTIVE TEMPERATURE...SUCH
ELEVATED CAPE WILL BE HARD TO REALIZE...MAKING THUNDERSTORM
FORMATION DIFFICULT TO ACHIEVE. THE CAVEAT HERE IS A WEAK
SHORTWAVE PROVIDING ADDITIONAL FORCING OVER THE MOUNTAINS IN
ADDITION TO THE DIURNAL HEATING. THUS EXPECT SHOWERS AND
THUNDERSTORMS TO DEVELOP OVER THE MOUNTAINS IN THE EARLY
AFTERNOON...AND REMAIN MOSTLY ANCHORED OVER THE MOUNTAINS WITH THE
EXCEPTION OF A COUPLE STORMS WHICH COULD IMPACT NEARBY LOWER
ELEVATIONS.
ANOTHER AREA OF INTEREST FOR CONVECTION TOMORROW AFTERNOON AND
EARLY EVENING WILL BE ACROSS FAR SOUTHEASTERN MONTANA. SOUTHERN
POWDER RIVER AND CARTER COUNTIES LIE JUST OUTSIDE THE NORTHERN
FRINGE OF A SLIGHT RISK OF SEVERE WEATHER FROM SPC. THE
SOUTHEASTERLY FLOW WILL CONTINUE TO BRING 50 DEGREE DEW POINT AIR
INTO THE SOUTHEAST CORNER OF THE STATE NEAR THE NOSE OF THE LOW-
LEVEL JET. THE BETTER INGREDIENTS FOR CONVECTION CERTAINLY APPEAR
FARTHER SOUTH WHERE THE TEMPERATURES ARE WARMER. SOUTHEAST MONTANA
WILL HAVE A PROBLEM WITH CAPPING AROUND 700MB ABOVE THE SLIGHTLY
COOLER SOUTHEASTERLY LOW-LEVEL FLOW. HOWEVER...FORECAST SOUNDINGS
FOR BROADUS SHOW A WEAKER CAP THAN AT MLS OR BHK. WITH MODELS
MOVING PRECIPITATION OVER LOCATIONS SOUTH OF BROADUS ALONG THE
NORTHEAST WYOMING BORDER...CERTAINLY CANNOT RULE OUT THE CHANCE OF
THUNDERSTORMS IN THIS SECTION OF THE FORECAST AREA.
THE THERMAL RIDGE WILL REMAIN OVER THE FORECAST AREA
OVERNIGHT...ALONG WITH SOUTHEASTERLY WINDS AHEAD OF THE SURFACE
TROUGH AND MID TO HIGH CLOUD COVER LINGERING FROM THE DAYS
CONVECTION. THIS WILL COMBINE TO PRODUCE WARM OVERNIGHT LOW
TEMPERATURES.
WEDNESDAY IS ANOTHER COMPLEX DAY FOR CONVECTION ACROSS THE
FORECAST AREA. THE APPROACHING PACIFIC THROUGH WILL INTRODUCE SOME
STRONGER QG FORCING OVER WESTERN ZONES BY TOMORROW AFTERNOON. THE
POSITION OF THE LOW FAVORS TAPPING INTO DRY AIR OVER THE GREAT
BASIN AND PULLING IT OVER THE FORECAST AREA. MEANWHILE THE BETTER
LOW LEVEL MOISTURE IS PUSHED NORTH AROUND THE LOW THROUGH THE
GLASGOW FORECAST AREA INTO GREAT FALLS FORECAST AREA. WITH THE
BETTER FORCING AND MOISTURE POSITIONED MAINLY NORTH AND WEST OF
THE FORECAST AREA...EXPECT WE WILL WATCH THE STRONGEST
THUNDERSTORMS MOVE BY TO OUR NORTH BY WEDNESDAY EVENING.
HOWEVER...SINCE NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA
WILL REMAIN ON THE FRINGES OF THESE BETTER INGREDIENTS HAVE CHOSEN
KEEP 50 POPS AND MENTION OF SEVERE IN THESE AREAS. TAPERED BACK
POPS FOR THE MORE SOUTHERN AND EASTERN LOCATIONS AND REMOVED THE
SEVERE WORDING.
TEMPERATURES ON WEDNESDAY WILL BE IN THE MID TO UPPER 80S FOR MOST
OF THE FORECAST AREA AS THE THERMAL RIDGE MOVES FARTHER EAST. ALSO
EXPECT THE SURFACE FRONT TO PUSH ACROSS THE FORECAST AREA FROM
WEST TO EAST BY LATE WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING.
EXPECT THE PRE FRONTAL WARMING WILL ALSO CONTRIBUTE TO WARMER HIGH
TEMPERATURES. CHURCH
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
PACIFIC LOW OVER THE NORTHWEST ON THURSDAY SHOULD HAVE SHUNTED
THE BEST LOW LEVEL MOISTURE NORTHEAST OF THE AREA BUT IT CLEARLY
IS SLOWER AND DEEPER KEEPING MORE CYCLONIC FLOW OVER THE AREA.
THIS SHOULD MAKE MOUNTAIN THUNDERSTORMS POSSIBLE MOVING OVER THE
PLAINS BUT WOULD EXPECT LACK OF DEEP MOISTURE TO LIMIT STORM
INTENSITY. BIG STORY ON THURSDAY IS THAT TEMPERATURES WILL BE
NEARLY 15 DEGREES COOLER THAN WEDNESDAY.
FRIDAY LOOKS SIMILAR TO THURSDAY THOUGH THE ECMWF HINTS A BIT OF
LOW LEVEL AIRMASS RECOVERY COMPARED TO THURSDAY BUT STILL DOES NOT
LOOK LIKE MORE THAN ISOLATED THUNDERSTORMS. SATURDAY THE UPPER LOW
EJECTS INTO SOUTHERN CANADA AND A TROUGH AXIS CROSSES MONTANA.
CONFLUENT FLOW ALOFT SHOULD HAVE A GOOD CHANCE AT SURPRESSING MOST
CONVECTION ACROSS THE WESTERN HALF OF THE AREA WHILE A COLD FRONT
MOVING THROUGH EASTERN MONTANA MAY TRY AND TRIGGER SOME MORE
CONVECTION.
HEIGHTS REMAIN SURPRESSED IN THE SUNDAY AND MONDAY TIME FRAME WITH
WEAK IMPULSES MOVING THROUGH THE AREA IN WEST SOUTHWESTERLY FLOW
ALOFT. TEMPERATURES WILL BE NEAR NORMAL AND WHILE THUNDER CANNOT
BE RULED OUT THE PATTERN DOES NOT FAVOR ANYTHING MORE THAN GENERIC
STORMS. BORSUM
&&
.AVIATION...
A WEAK DISTURBANCE WILL BRING ISOLD -SHRA NEAR KSHR THIS MORNING.
LOOK FOR ISOLD TO SCT SHOWERS/TSTMS THIS AFTERNOON AND EVENING...
WITH GREATEST COVERAGE NEAR THE MTNS AND FOOTHILLS...PERHAPS
IMPACTING KLVM AND KSHR. VFR WILL PREVAIL BUT LOCAL MVFR IS
POSSIBLE IN ANY STRONGER STORMS. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 088 062/088 053/077 050/073 050/075 051/076 051/079
2/T 22/T 22/T 22/T 22/T 22/T 22/T
LVM 089 050/089 047/072 040/070 042/071 047/078 046/081
3/T 33/T 23/T 22/T 23/T 32/T 22/T
HDN 090 059/090 053/078 053/074 050/076 051/077 051/079
1/B 22/T 22/T 33/T 23/T 32/T 22/T
MLS 086 060/090 058/081 055/074 055/077 055/079 055/080
1/B 22/T 42/T 33/T 33/T 33/T 22/T
4BQ 086 059/092 055/081 055/075 052/077 052/079 051/080
3/T 21/B 22/T 33/T 33/T 33/T 22/T
BHK 081 057/086 057/080 054/075 053/074 052/076 052/076
1/U 22/T 32/T 45/T 54/T 33/T 32/T
SHR 083 052/088 050/078 050/073 048/075 047/076 048/078
3/T 22/T 22/T 33/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 181016
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
416 AM MDT TUE JUN 18 2013
.SHORT TERM...VALID FOR TDY AND WED...
YESTERDAY AFTERNOON SAW SOME ISOLATED SHOWERS AND THUNDERSTORMS
OVER MOUNTAIN LOCATIONS...BUT THOSE FAILED TO MOVE OFF INTO THE
LOWER ELEVATIONS. ENVIRONMENTAL CONDITIONS TODAY WILL BE SIMILAR
TO YESTERDAY. DEW POINTS ARE EXPECTED TO BE IN THE MID 40S TO LOWER
50S ESPECIALLY FOR CENTRAL AND WESTERN ZONES. THIS LOW-LEVEL
MOISTURE IS MARGINALLY ENOUGH TO CONSIDER THE THREAT OF
THUNDERSTORMS MOVING OFF THE MOUNTAINS AND INTO THE PLAINS ACROSS
WESTERN ZONES. HOWEVER...THE AMOUNT OF MOISTURE IS ALSO LIMITING
IN THE SENSE THAT LFCS ARE VERY HIGH...ON THE ORDER OF 10K FEET.
ALTHOUGH TEMPERATURES ARE EXPECTED TO RISE TO THE UPPER 80S TO
NEAR 90...WHICH IS CLOSE TO THE CONVECTIVE TEMPERATURE...SUCH
ELEVATED CAPE WILL BE HARD TO REALIZE...MAKING THUNDERSTORM
FORMATION DIFFICULT TO ACHIEVE. THE CAVEAT HERE IS A WEAK
SHORTWAVE PROVIDING ADDITIONAL FORCING OVER THE MOUNTAINS IN
ADDITION TO THE DIURNAL HEATING. THUS EXPECT SHOWERS AND
THUNDERSTORMS TO DEVELOP OVER THE MOUNTAINS IN THE EARLY
AFTERNOON...AND REMAIN MOSTLY ANCHORED OVER THE MOUNTAINS WITH THE
EXCEPTION OF A COUPLE STORMS WHICH COULD IMPACT NEARBY LOWER
ELEVATIONS.
ANOTHER AREA OF INTEREST FOR CONVECTION TOMORROW AFTERNOON AND
EARLY EVENING WILL BE ACROSS FAR SOUTHEASTERN MONTANA. SOUTHERN
POWDER RIVER AND CARTER COUNTIES LIE JUST OUTSIDE THE NORTHERN
FRINGE OF A SLIGHT RISK OF SEVERE WEATHER FROM SPC. THE
SOUTHEASTERLY FLOW WILL CONTINUE TO BRING 50 DEGREE DEW POINT AIR
INTO THE SOUTHEAST CORNER OF THE STATE NEAR THE NOSE OF THE LOW-
LEVEL JET. THE BETTER INGREDIENTS FOR CONVECTION CERTAINLY APPEAR
FARTHER SOUTH WHERE THE TEMPERATURES ARE WARMER. SOUTHEAST MONTANA
WILL HAVE A PROBLEM WITH CAPPING AROUND 700MB ABOVE THE SLIGHTLY
COOLER SOUTHEASTERLY LOW-LEVEL FLOW. HOWEVER...FORECAST SOUNDINGS
FOR BROADUS SHOW A WEAKER CAP THAN AT MLS OR BHK. WITH MODELS
MOVING PRECIPITATION OVER LOCATIONS SOUTH OF BROADUS ALONG THE
NORTHEAST WYOMING BORDER...CERTAINLY CANNOT RULE OUT THE CHANCE OF
THUNDERSTORMS IN THIS SECTION OF THE FORECAST AREA.
THE THERMAL RIDGE WILL REMAIN OVER THE FORECAST AREA
OVERNIGHT...ALONG WITH SOUTHEASTERLY WINDS AHEAD OF THE SURFACE
TROUGH AND MID TO HIGH CLOUD COVER LINGERING FROM THE DAYS
CONVECTION. THIS WILL COMBINE TO PRODUCE WARM OVERNIGHT LOW
TEMPERATURES.
WEDNESDAY IS ANOTHER COMPLEX DAY FOR CONVECTION ACROSS THE
FORECAST AREA. THE APPROACHING PACIFIC THROUGH WILL INTRODUCE SOME
STRONGER QG FORCING OVER WESTERN ZONES BY TOMORROW AFTERNOON. THE
POSITION OF THE LOW FAVORS TAPPING INTO DRY AIR OVER THE GREAT
BASIN AND PULLING IT OVER THE FORECAST AREA. MEANWHILE THE BETTER
LOW LEVEL MOISTURE IS PUSHED NORTH AROUND THE LOW THROUGH THE
GLASGOW FORECAST AREA INTO GREAT FALLS FORECAST AREA. WITH THE
BETTER FORCING AND MOISTURE POSITIONED MAINLY NORTH AND WEST OF
THE FORECAST AREA...EXPECT WE WILL WATCH THE STRONGEST
THUNDERSTORMS MOVE BY TO OUR NORTH BY WEDNESDAY EVENING.
HOWEVER...SINCE NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA
WILL REMAIN ON THE FRINGES OF THESE BETTER INGREDIENTS HAVE CHOSEN
KEEP 50 POPS AND MENTION OF SEVERE IN THESE AREAS. TAPERED BACK
POPS FOR THE MORE SOUTHERN AND EASTERN LOCATIONS AND REMOVED THE
SEVERE WORDING.
TEMPERATURES ON WEDNESDAY WILL BE IN THE MID TO UPPER 80S FOR MOST
OF THE FORECAST AREA AS THE THERMAL RIDGE MOVES FARTHER EAST. ALSO
EXPECT THE SURFACE FRONT TO PUSH ACROSS THE FORECAST AREA FROM
WEST TO EAST BY LATE WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING.
EXPECT THE PRE FRONTAL WARMING WILL ALSO CONTRIBUTE TO WARMER HIGH
TEMPERATURES. CHURCH
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
PACIFIC LOW OVER THE NORTHWEST ON THURSDAY SHOULD HAVE SHUNTED
THE BEST LOW LEVEL MOISTURE NORTHEAST OF THE AREA BUT IT CLEARLY
IS SLOWER AND DEEPER KEEPING MORE CYCLONIC FLOW OVER THE AREA.
THIS SHOULD MAKE MOUNTAIN THUNDERSTORMS POSSIBLE MOVING OVER THE
PLAINS BUT WOULD EXPECT LACK OF DEEP MOISTURE TO LIMIT STORM
INTENSITY. BIG STORY ON THURSDAY IS THAT TEMPERATURES WILL BE
NEARLY 15 DEGREES COOLER THAN WEDNESDAY.
FRIDAY LOOKS SIMILAR TO THURSDAY THOUGH THE ECMWF HINTS A BIT OF
LOW LEVEL AIRMASS RECOVERY COMPARED TO THURSDAY BUT STILL DOES NOT
LOOK LIKE MORE THAN ISOLATED THUNDERSTORMS. SATURDAY THE UPPER LOW
EJECTS INTO SOUTHERN CANADA AND A TROUGH AXIS CROSSES MONTANA.
CONFLUENT FLOW ALOFT SHOULD HAVE A GOOD CHANCE AT SURPRESSING MOST
CONVECTION ACROSS THE WESTERN HALF OF THE AREA WHILE A COLD FRONT
MOVING THROUGH EASTERN MONTANA MAY TRY AND TRIGGER SOME MORE
CONVECTION.
HEIGHTS REMAIN SURPRESSED IN THE SUNDAY AND MONDAY TIME FRAME WITH
WEAK IMPULSES MOVING THROUGH THE AREA IN WEST SOUTHWESTERLY FLOW
ALOFT. TEMPERATURES WILL BE NEAR NORMAL AND WHILE THUNDER CANNOT
BE RULED OUT THE PATTERN DOES NOT FAVOR ANYTHING MORE THAN GENERIC
STORMS. BORSUM
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL WITH MAINLY MOUNTAIN THUNDERSTORMS IN
THE AFTERNOON AND EVENING. IMPACTS ON TERMINAL SITES WILL BE
LIMITED BUT A STORM MOVING OFF FO THE MOUNTAINS AND IMPACT KLVM
CANNOT BE RULES OUT. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 088 062/088 053/077 050/073 050/075 051/076 051/079
2/T 22/T 22/T 22/T 22/T 22/T 22/T
LVM 089 050/089 047/072 040/070 042/071 047/078 046/081
4/T 33/T 23/T 22/T 23/T 32/T 22/T
HDN 090 059/090 053/078 053/074 050/076 051/077 051/079
2/T 22/T 22/T 33/T 23/T 32/T 22/T
MLS 086 060/090 058/081 055/074 055/077 055/079 055/080
1/U 22/T 42/T 33/T 33/T 33/T 22/T
4BQ 086 059/092 055/081 055/075 052/077 052/079 051/080
1/B 21/B 22/T 33/T 33/T 33/T 22/T
BHK 081 057/086 057/080 054/075 053/074 052/076 052/076
1/U 22/T 32/T 45/T 54/T 33/T 32/T
SHR 083 052/088 050/078 050/073 048/075 047/076 048/078
3/T 22/T 22/T 33/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 180257
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
857 PM MDT MON JUN 17 2013
.UPDATE...
HAVE MADE SOME MINOR ADJUSTMENTS TO CURRENT FORECAST FOR TONIGHT.
UPPER RIDGE WILL SHIFT SLOWLY EASTWARD OVERNIGHT AS A LOW PRESSURE
TROUGH MOVES ON TO THE WEST COAST. WEAK VORTICITY MOVING UNDER THE
RIDGE THIS EVENING HAS BROUGHT ISOLATED CONVECTION TO THE
MOUNTAINS AND ALONG OUR FAR SOUTHERN ZONES. THIS ACTIVITY HAS
ENDED OVER OUR SOUTHERN ZONES AS INCREASING EASTERLY UPSLOPE FLOW
HAS SETUP A TEMPERATURE INVERSION. DID KEEP A SLIGHT CHANCE OF
ISOLATED SHOWERS AND THUNDERSTORMS ACROSS OUR WESTERN ZONES AS
ANOTHER SHORT WAVE ROTATES ACROSS THAT AREA OVERNIGHT. REMAINDER
OF THE FORECAST ON TRACK AND NO OTHER CHANGES MADE. RICHMOND
&&
.SHORT TERM...VALID FOR TUE AND WED...
AFTERNOON INSTABILITY...WEAK SHORTWAVES AND OROGRAPHIC LIFT WERE
CREATING CUMULUS...AS SEEN ON VISIBLE SATELLITE IMAGERY...AS WELL
AS SPOTTY CONVECTION...SEEN ON RADAR. MODELS HAD CAPES AT 1000
J/KG OR LOWER THIS EVENING. HIGHEST SHEAR WAS OVER SE MT AT
00Z...BUT CAPES WILL BE QUITE LOW...SO NOT EXPECTING ANY SEVERE
WEATHER. INHERITED POPS WERE IN GOOD SHAPE...REFLECTING CHANCES
FOR CONVECTION OVER AND NEAR THE MOUNTAINS...AND OVER THE
SE DUE TO UPPER JET.
SHORTWAVES WILL CONTINUE MOVING THROUGH THE UPPER RIDGE TUE AND
TUE NIGHT. THE RIDGE WILL BREAK DOWN TUE NIGHT AS A STRONG UPPER
LOW OVER THE PACIFIC NW ROTATES TOWARD THE AREA. DIFLUENCE WILL
INCREASE OVER THE AREA THROUGH WED AS THE LOW BECOMES NEGATIVELY
TILTED. PRECIPITABLE WATERS WILL AVERAGE AROUND 0.80 INCHES
THROUGH THE PERIOD SO PLENTY OF MOISTURE WAS AVAILABLE FOR
CONVECTION. ON TUE...CAPE INCREASES FROM W TO E ACROSS THE AREA
WITH AROUND 2000 J/KG ALONG THE E MT BORDER. SHEAR WAS NOT OVERLY
STRONG. SOUNDINGS HAD AN INVERTED-V APPEARANCE...MAINLY W OF KBIL.
WILL MENTION POSSIBLE GUSTY WINDS AND SMALL HAIL WITH
THUNDERSTORMS. STORMS WILL BE OVER AND NEAR THE MOUNTAINS ON TUE
AND SPREAD E DURING THE EVENING AS DIFLUENCE INCREASES AND LOW-
LEVEL JET STRENGTHENS OVER THE PLAINS.
Q-VECTOR CONVERGENCE WILL STRENGTHEN OVER THE AREA WED AND WED
NIGHT AS STRONGER SHORTWAVES MOVE INTO THE REGION FROM THE UPPER
LOW TO THE W. SEVERE PARAMETERS LOOKED STRONGER THAN ON TUE...WITH
CAPES GREATER THAN 2000 J/KG E OF KBIL AT 18Z ON THE GFS. GFS
PUSHES THE CAPE TO THE N BY 00Z THU. WRF TAKES LONGER TO MOVE THE
CAPE OUT OF THE AREA WED AFTERNOON. MODELS HAD THE HIGH CAPES
OVER THE FAR E ZONES AT 06Z THU. SHEAR DID NOT LOOK VERY STRONG
WED ON THE GFS. ON THE WRF...HOWEVER...VALUES INCREASED OVER THE W
IN THE AFTERNOON. THE GFS INCREASED THE SHEAR OVER THE AREA WED
NIGHT. GFS ALSO DEVELOPED ALL THE QPF TO THE N OF THE AREA ALONG
THE WARM FRONT ON WED...WHILE THE WRF BROUGHT PRECIPITATION IN
FROM THE W WITH THE SYSTEM/S COLD FRONT. POPS REFLECTED A
COMPROMISE BETWEEN THE TWO MODELS. WILL MENTION POSSIBLE SEVERE
FOR BOTH THE AFTERNOON AND THE OVERNIGHT PERIODS. THE COLD FRONT
WILL CROSS THE AREA WED NIGHT. SEVERE THUNDERSTORMS WILL BE
POSSIBLE OVER THE EASTERN ZONES AHEAD OF THE FRONT AFTER 06Z THU.
RAISED HIGH TEMPERATURES AHEAD OF THE COLD FRONT ON WED. ARTHUR
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
ONLY MINOR ADJUSTMENTS TO THE FORECAST THIS AFTERNOON. AREA WILL
BE UNDER THE INFLUENCE OF A PACIFIC LOW THURSDAY INTO SUNDAY. MOST
MODEL SOLUTIONS KEEP CORE OF THE LOW JUST TO THE WEST PUTTING THE
FORECAST AREA IN SOUTHERLY DIVERGENT FLOW WHICH IS A GOOD
PRECIPITATION PATTERN. THUNDERSTORMS LOOK LIKE A GOOD BET EACH DAY
WITH STRENGTH OF THE STORMS DEPENDING ON LOW LEVEL PLAINS MOISTURE
ADVECTION AS WELL AS THE AMOUNT OF HEATING. WITH PROXIMITY TO THE
LOW THERE WILL BE A GOOD DEAL OF CLOUD COVER THAT MAY HOLD
TEMPERATURES DOWN MINIMIZING STORM STRENGTH...BUT CERTAINLY LOOKS
LIKE AT LEAST SOME THREAT FOR SEVERE STORMS THURSDAY AND FRIDAY.
CURRENT SCATTERED PRECIPITATION CHANCES LOOK REASONABLE AND AS
MODELS MERGE ON A SOLUTION WILL BE ABLE TO BETTER PINPOINT AREAS
OF HIGHER POPS AND STRONGER STORMS. AS THE CORE OF THE UPPER LOW
MOVES OVER THE AREA SATURDAY INTO SUNDAY EXPECT COOLER
TEMPERATURES AND MORE SHOWER ACTIVITY AS OPPOSED TO THUNDERSTORMS.
WEAK RIDGING WILL DEVELOP MONDAY FOR DRIER AND WARMER CONDITIONS.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TONIGHT AND TUESDAY.
A LOW PROBABILITY OF THUNDERSTORMS EXISTS OVER THE MOUNTAINS AND
NEARBY LOCATIONS THOUGH. ANOTHER CHANCE OF STORMS WILL RETURN TO
SOUTH CENTRAL MT AND NORTH CENTRAL WY BY LATE TUESDAY AFTERNOON.
HOWEVER...CONFIDENCE IN THAT POTENTIAL WAS TOO LOW TO MENTION IN
ANY OF THE 00 UTC TERMINAL FORECASTS. SCHULTZ
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 056/086 060/088 053/077 050/073 050/075 051/074 051/079
12/T 23/T 32/T 33/T 22/T 22/T 22/T
LVM 046/085 049/089 047/072 040/070 042/074 047/076 046/081
24/T 33/T 23/T 33/T 22/T 23/T 32/T
HDN 053/088 059/090 053/078 053/074 050/076 051/075 051/079
12/T 22/T 33/T 33/T 22/T 22/T 22/T
MLS 056/087 060/090 058/081 055/074 055/077 055/077 055/080
11/U 22/T 33/T 33/T 33/T 33/T 22/T
4BQ 051/087 059/092 055/081 055/075 052/077 052/077 051/080
11/U 21/U 23/T 33/T 33/T 33/T 22/T
BHK 053/083 056/086 057/080 054/075 053/074 052/074 052/076
11/U 22/T 32/T 44/T 43/T 33/T 32/T
SHR 054/085 052/088 050/078 050/073 048/075 047/074 048/078
23/T 22/T 23/T 33/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 172051
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
251 PM MDT MON JUN 17 2013
.SHORT TERM...VALID FOR TUE AND WED...
AFTERNOON INSTABILITY...WEAK SHORTWAVES AND OROGRAPHIC LIFT WERE
CREATING CUMULUS...AS SEEN ON VISIBLE SATELLITE IMAGERY...AS WELL
AS SPOTTY CONVECTION...SEEN ON RADAR. MODELS HAD CAPES AT 1000
J/KG OR LOWER THIS EVENING. HIGHEST SHEAR WAS OVER SE MT AT
00Z...BUT CAPES WILL BE QUITE LOW...SO NOT EXPECTING ANY SEVERE
WEATHER. INHERITED POPS WERE IN GOOD SHAPE...REFLECTING CHANCES
FOR CONVECTION OVER AND NEAR THE MOUNTAINS...AND OVER THE
SE DUE TO UPPER JET.
SHORTWAVES WILL CONTINUE MOVING THROUGH THE UPPER RIDGE TUE AND
TUE NIGHT. THE RIDGE WILL BREAK DOWN TUE NIGHT AS A STRONG UPPER
LOW OVER THE PACIFIC NW ROTATES TOWARD THE AREA. DIFLUENCE WILL
INCREASE OVER THE AREA THROUGH WED AS THE LOW BECOMES NEGATIVELY
TILTED. PRECIPITABLE WATERS WILL AVERAGE AROUND 0.80 INCHES
THROUGH THE PERIOD SO PLENTY OF MOISTURE WAS AVAILABLE FOR
CONVECTION. ON TUE...CAPE INCREASES FROM W TO E ACROSS THE AREA
WITH AROUND 2000 J/KG ALONG THE E MT BORDER. SHEAR WAS NOT OVERLY
STRONG. SOUNDINGS HAD AN INVERTED-V APPEARANCE...MAINLY W OF KBIL.
WILL MENTION POSSIBLE GUSTY WINDS AND SMALL HAIL WITH
THUNDERSTORMS. STORMS WILL BE OVER AND NEAR THE MOUNTAINS ON TUE
AND SPREAD E DURING THE EVENING AS DIFLUENCE INCREASES AND LOW-
LEVEL JET STRENGTHENS OVER THE PLAINS.
Q-VECTOR CONVERGENCE WILL STRENGTHEN OVER THE AREA WED AND WED
NIGHT AS STRONGER SHORTWAVES MOVE INTO THE REGION FROM THE UPPER
LOW TO THE W. SEVERE PARAMETERS LOOKED STRONGER THAN ON TUE...WITH
CAPES GREATER THAN 2000 J/KG E OF KBIL AT 18Z ON THE GFS. GFS
PUSHES THE CAPE TO THE N BY 00Z THU. WRF TAKES LONGER TO MOVE THE
CAPE OUT OF THE AREA WED AFTERNOON. MODELS HAD THE HIGH CAPES
OVER THE FAR E ZONES AT 06Z THU. SHEAR DID NOT LOOK VERY STRONG
WED ON THE GFS. ON THE WRF...HOWEVER...VALUES INCREASED OVER THE W
IN THE AFTERNOON. THE GFS INCREASED THE SHEAR OVER THE AREA WED
NIGHT. GFS ALSO DEVELOPED ALL THE QPF TO THE N OF THE AREA ALONG
THE WARM FRONT ON WED...WHILE THE WRF BROUGHT PRECIPITATION IN
FROM THE W WITH THE SYSTEM/S COLD FRONT. POPS REFLECTED A
COMPROMISE BETWEEN THE TWO MODELS. WILL MENTION POSSIBLE SEVERE
FOR BOTH THE AFTERNOON AND THE OVERNIGHT PERIODS. THE COLD FRONT
WILL CROSS THE AREA WED NIGHT. SEVERE THUNDERSTORMS WILL BE
POSSIBLE OVER THE EASTERN ZONES AHEAD OF THE FRONT AFTER 06Z THU.
RAISED HIGH TEMPERATURES AHEAD OF THE COLD FRONT ON WED. ARTHUR
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
ONLY MINOR ADJUSTMENTS TO THE FORECAST THIS AFTERNOON. AREA WILL
BE UNDER THE INFLUENCE OF A PACIFIC LOW THURSDAY INTO SUNDAY. MOST
MODEL SOLUTIONS KEEP CORE OF THE LOW JUST TO THE WEST PUTTING THE
FORECAST AREA IN SOUTHERLY DIVERGENT FLOW WHICH IS A GOOD
PRECIPITATION PATTERN. THUNDERSTORMS LOOK LIKE A GOOD BET EACH DAY
WITH STRENGTH OF THE STORMS DEPENDING ON LOW LEVEL PLAINS MOISTURE
ADVECTION AS WELL AS THE AMOUNT OF HEATING. WITH PROXIMITY TO THE
LOW THERE WILL BE A GOOD DEAL OF CLOUD COVER THAT MAY HOLD
TEMPERATURES DOWN MINIMIZING STORM STRENGTH...BUT CERTAINLY LOOKS
LIKE AT LEAST SOME THREAT FOR SEVERE STORMS THURSDAY AND FRIDAY.
CURRENT SCATTERED PRECIPITATION CHANCES LOOK REASONABLE AND AS
MODELS MERGE ON A SOLUTION WILL BE ABLE TO BETTER PINPOINT AREAS
OF HIGHER POPS AND STRONGER STORMS. AS THE CORE OF THE UPPER LOW
MOVES OVER THE AREA SATURDAY INTO SUNDAY EXPECT COOLER
TEMPERATURES AND MORE SHOWER ACTIVITY AS OPPOSED TO THUNDERSTORMS.
WEAK RIDGING WILL DEVELOP MONDAY FOR DRIER AND WARMER CONDITIONS.
&&
.AVIATION...
SCATTERED THUNDERSTORMS WILL CONTINUE INTO THE LATE EVENING SOUTH
OF A BROADUS TO BILLINGS TO HARLOWTON LINE...WITH LOCAL MVFR
CONDITIONS POSSIBLE. OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH
MID DAY TUESDAY. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 056/086 060/088 053/077 050/073 050/075 051/074 051/079
22/T 23/T 32/T 33/T 22/T 22/T 22/T
LVM 046/085 049/089 047/072 040/070 042/074 047/076 046/081
34/T 33/T 23/T 33/T 22/T 23/T 32/T
HDN 053/088 059/090 053/078 053/074 050/076 051/075 051/079
12/T 22/T 33/T 33/T 22/T 22/T 22/T
MLS 056/087 060/090 058/081 055/074 055/077 055/077 055/080
11/U 22/T 33/T 33/T 33/T 33/T 22/T
4BQ 051/087 059/092 055/081 055/075 052/077 052/077 051/080
11/U 21/U 23/T 33/T 33/T 33/T 22/T
BHK 053/083 056/086 057/080 054/075 053/074 052/074 052/076
11/U 22/T 32/T 44/T 43/T 33/T 32/T
SHR 054/085 052/088 050/078 050/073 048/075 047/074 048/078
23/T 22/T 23/T 33/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 171454
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
854 AM MDT MON JUN 17 2013
.UPDATE...
JUST A FEW CHANGES FOR THE MORNING UPDATE. VISIBLE SATELLITE
DEPICTED CLOUDS MOVING E OUT OF THE EASTERN PART OF THE FORECAST
AREA THIS MORNING. THE CLOUDS WERE ASSOCIATED WITH A SHORTWAVE
ROTATING OUT OF NE MT AND THE TAIL END OF A JET. WEAK ENERGY WILL
MOVE INTO THE REGION THIS AFTERNOON TRIGGERING THE DEVELOPMENT OF
THUNDERSTORMS OVER THE MOUNTAINS. JET ENERGY OVER E MT/SD WILL
CREATE CONVECTION OVER THE BLACK HILLS WHICH THE MODELS SUGGESTED
COULD MOVE INTO SE MT. AFTERNOON POPS REFLECTED THE SITUATION WELL
EXCEPT HAVE PAIRED BACK POPS FURTHER TO THE W TO TAKE OUT KBIL AND
NEARBY AREAS. BUFKIT SOUNDINGS HAD A LOT OF CONVECTIVE INHIBITION
AWAY FROM THE MOUNTAINS THIS AFTERNOON SO PRECIPITATION SHOULD BE
CONFINED TO AREAS OVER AND NEAR THE MOUNTAINS. LATE MORNING
CONVECTION WAS POSSIBLE OVER AND NEAR THE NE BIG HORNS BASED ON
MODEL QPF AND WEAK SHORTWAVE ENERGY. OTHERWISE GFS AND WRF WERE
OVERDONE IN THEIR QPF ALONG THE MT/WY BORDER THIS MORNING. HRRR
WAS HANDLING THE SITUATION BETTER THIS MORNING THAN THE OTHER
MODELS...BUT KEPT THE FORECAST AREA PRECIPITATION-FREE THROUGH THE
DAY. GIVEN THE APPROACH OF THE SHORTWAVES AND ELEVATED
CAPE...MOUNTAINS SHOULD AT LEAST GET SOME CONVECTION. WILL WAIT TO
SEE HOW THE AFTERNOON DEVELOPS BEFORE MAKING ANY EVENING POPS
ADJUSTMENTS. TEMPERATURES WERE ON TRACK WITH MIXING BETWEEN 850 MB
AND 700 MB. ADJUSTED WINDS TO FIT LATEST TRENDS BETTER. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND TUE...
THE WEATHER PATTERN WILL SLOWLY GROW MORE UNSETTLED FOR TODAY AND
TOMORROW AS EASTERLY SURFACE FLOW BECOMES ESTABLISHED UNDER
RIDGING ALOFT AND A PACIFIC LOW SLOWLY APPROACHES THE FORECAST
AREA. YESTERDAY SAW AN INCREASE IN CONVECTION OVER OUR SOUTHERN
MOUNTAIN LOCATIONS AND INTO WYOMING. FOR TODAY...THE INCREASING
EASTERLY TO SOUTHEASTERLY LOW-LEVEL FLOW WILL ACT TO INCREASE AND
DEEPEN LOW-LEVEL MOISTURE ACROSS THE PLAINS OF THE FORECAST AREA.
WITH SIMILAR MOISTURE AND DIURNAL HEATING OVER THE MOUNTAINS TODAY
AS YESTERDAY...EXPECT TO SEE ANOTHER ROUND OF AFTERNOON CONVECTION
DEVELOP OVER THE MOUNTAIN LOCATIONS. TODAY...HOWEVER...EXPECT THAT
THE SLOWLY INCREASING MOISTURE OVER THE PLAINS WILL ALLOW SOME OF
THE STRONGER SHOWERS/THUNDERSTORMS TO TRACK FARTHER OFF THE
MOUNTAINS BEFORE THE CAPPING BECOMES TO STRONG FOR THEM. THUS FOR
TODAY...HAVE INCREASED POPS OVER THE FOOTHILLS LOCATIONS AND
NEARBY PLAINS TO SHOW ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS FOR LATER IN THE AFTERNOON INTO THE EARLY EVENING.
FOR TUESDAY...PERSISTENT LOW-LEVEL EASTERLY FLOW WILL CONTINUE
INCREASE LOW-LEVEL MOISTURE. A WEAK DISTURBANCE UNDERCUTTING
THE RIDGE IN THE SOUTHWESTERLY FLOW ALOFT WILL AID IN ENHANCING
SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS TUESDAY AFTERNOON
BEFORE THEY TRACK OFF THE MOUNTAINS TO THE NORTH ACROSS THE NEARBY
FOOTHILLS AND PLAINS. ANOTHER ROUND OF CONVECTION IS EXPECTED TO
DEVELOP OVER EASTERN WYOMING AND COULD IMPACT FAR SOUTHEASTERN
MONTANA AS IT PUSHED OUT INTO SOUTH DAKOTA BY THE EVENING. THUS
FOR TUESDAY...HAVE INCREASED POPS TO SCATTERED OVER THE MOUNTAINS
AND THE CORRIDOR FROM LIVINGSTON TO HARLOWTON TO JUDITH GAP. ALSO
INCREASED POPS FOR SHERIDAN WY EAST TOWARD BROADUS AND ALZADA.
TEMPERATURES BOTH DAYS WILL BE RUNNING ABOVE NORMAL THANKS TO THE
RIDGING ALOFT AND 700 MB TEMPERATURES RUNNING AROUND +5 TO +10 C.
OVERNIGHT LOWS BOTH DAYS WILL BE HELD UP BY LIGHT EASTERLY WINDS
AND ANY REMAINING MIDDLE AND HIGH CLOUD COVER FROM CONVECTION
EARLIER IN THE DAY/EVENING. CHURCH
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
EXTENDED PERIOD WILL BE IMPACTED BY AN UPPER LEVEL LOW OVER THE
PACIFIC NORTHWEST ON WEDNESDAY WHICH TRIES TO BEGIN MOVING BUT IS
OVER SOUTHERN SASKATCHEWAN BY SUNDAY. THIS SLOW MOVEMENT MEANS
THIS LOW WILL INFLUENCE THE WEATHER OVER MONTANA AND WYOMING BUT
ITS TRACK NORTH OF THE AREA MEANS ITS NOT STRONG FOR THE AREA
DYNAMICALLY BUT WILL GENERALLY KEEP CONVECTION IN THE FORECAST.
WEDNESDAY IS THE DAY FOR HIGHEST STRONG CONVECTION POTENTIAL AS AN
IMPULSE EJECTS AROUND THE LOW GIVING A NEGATIVE TILT TO THE FLOW
ALOFT. THE PATTERN ALSO ADVECTS IN SOME VERY WARM TEMPERATURES
ALOFT AND TRIES TO BRING A DRIER WESTERLY SURFACE FLOW FOR THE
WESTERN ZONES. CAPPING AND DOWNSLOPE COULD ERODE ANY CONVECTIVE
THREAT...BUT CONVECTIVE PARAMETERS ARE VERY HIGH WITH CAPES
PROGGED AROUND 2000-3000 J/KG AND DECENT LOW LEVEL SHEAR. BOTTOM
LINE...WEDNESDAY HAS SOLID UNCERTAINITY WITH IT AND COULD BE A
SIGNIFICANT SEVERE WEATHER DAY BUT AT THIS POINT IT IS EXPECTED
THAT GREATEST THREAT IS IN NORTHERN MONTANA.
WHAT HAS CHANGED IN THE MOST RECENT RUNS IS LOW DOES NOT EJECT AS
QUICKLY AS PREVIOUSLY INDICATED...WHICH GIVES A BETTER CHANCE FOR
THUNDER THURSDAY AND FRIDAY. TEMPERATURES WILL BE COOLER SO
THUNDER INTENSITY MAY NOT BE AS STRONG BUT UPPER LEVEL WINDS WILL
BE STRONGER SO SOME SHEAR IS AVAILABLE.
SATURDAY UPPER LOW AXIS CROSSES THE AREA AND THIS SHIFTS THE
MOISTURE NORTHEASTWARD AND IT DOES START LOOKING DRY SUNDAY INTO
MONDAY. TEMPERATURES WILL BE SEASONABLE AND AROUND 80 DEGREES.
BORSUM
&&
.AVIATION...
MOSTLY SUNNY CONDITIONS UNTIL AFTERNOON WITH MOUNTAIN CUMULUS
DEVELOPMENT. THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON AND
HAVE A BETTER CHANCE MOVING ONTO THE WESTERN AND CENTRAL PLAINS.
THUNDERSTORMS ARE POSSIBLE FOR KBIL...KLVM AND KSHR INTO THE
EVENING. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 080 058/086 061/086 056/077 050/076 050/075 051/074
1/B 22/T 24/T 42/T 33/T 22/T 22/T
LVM 081 047/085 053/083 049/072 040/073 042/074 047/076
3/T 34/T 33/T 33/T 33/T 22/T 23/T
HDN 080 056/088 056/089 058/078 053/077 050/076 051/075
1/B 12/T 23/T 33/T 33/T 22/T 22/T
MLS 079 057/087 061/088 062/081 055/077 055/077 055/077
1/U 11/U 23/T 33/T 33/T 33/T 33/T
4BQ 079 055/087 058/090 059/081 055/078 052/077 052/077
2/T 11/N 22/T 23/T 33/T 33/T 33/T
BHK 075 055/083 061/083 062/080 054/078 053/074 052/074
1/U 11/N 22/T 32/T 44/T 43/T 33/T
SHR 079 053/085 055/086 055/078 050/076 048/075 047/074
2/T 23/T 22/T 23/T 33/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 171017
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
417 AM MDT MON JUN 17 2013
.SHORT TERM...VALID FOR TDY AND TUE...
THE WEATHER PATTERN WILL SLOWLY GROW MORE UNSETTLED FOR TODAY AND
TOMORROW AS EASTERLY SURFACE FLOW BECOMES ESTABLISHED UNDER
RIDGING ALOFT AND A PACIFIC LOW SLOWLY APPROACHES THE FORECAST
AREA. YESTERDAY SAW AN INCREASE IN CONVECTION OVER OUR SOUTHERN
MOUNTAIN LOCATIONS AND INTO WYOMING. FOR TODAY...THE INCREASING
EASTERLY TO SOUTHEASTERLY LOW-LEVEL FLOW WILL ACT TO INCREASE AND
DEEPEN LOW-LEVEL MOISTURE ACROSS THE PLAINS OF THE FORECAST AREA.
WITH SIMILAR MOISTURE AND DIURNAL HEATING OVER THE MOUNTAINS TODAY
AS YESTERDAY...EXPECT TO SEE ANOTHER ROUND OF AFTERNOON CONVECTION
DEVELOP OVER THE MOUNTAIN LOCATIONS. TODAY...HOWEVER...EXPECT THAT
THE SLOWLY INCREASING MOISTURE OVER THE PLAINS WILL ALLOW SOME OF
THE STRONGER SHOWERS/THUNDERSTORMS TO TRACK FARTHER OFF THE
MOUNTAINS BEFORE THE CAPPING BECOMES TO STRONG FOR THEM. THUS FOR
TODAY...HAVE INCREASED POPS OVER THE FOOTHILLS LOCATIONS AND
NEARBY PLAINS TO SHOW ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS FOR LATER IN THE AFTERNOON INTO THE EARLY EVENING.
FOR TUESDAY...PERSISTENT LOW-LEVEL EASTERLY FLOW WILL CONTINUE
INCREASE LOW-LEVEL MOISTURE. A WEAK DISTURBANCE UNDERCUTTING
THE RIDGE IN THE SOUTHWESTERLY FLOW ALOFT WILL AID IN ENHANCING
SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS TUESDAY AFTERNOON
BEFORE THEY TRACK OFF THE MOUNTAINS TO THE NORTH ACROSS THE NEARBY
FOOTHILLS AND PLAINS. ANOTHER ROUND OF CONVECTION IS EXPECTED TO
DEVELOP OVER EASTERN WYOMING AND COULD IMPACT FAR SOUTHEASTERN
MONTANA AS IT PUSHED OUT INTO SOUTH DAKOTA BY THE EVENING. THUS
FOR TUESDAY...HAVE INCREASED POPS TO SCATTERED OVER THE MOUNTAINS
AND THE CORRIDOR FROM LIVINGSTON TO HARLOWTON TO JUDITH GAP. ALSO
INCREASED POPS FOR SHERIDAN WY EAST TOWARD BROADUS AND ALZADA.
TEMPERATURES BOTH DAYS WILL BE RUNNING ABOVE NORMAL THANKS TO THE
RIDGING ALOFT AND 700 MB TEMPERATURES RUNNING AROUND +5 TO +10 C.
OVERNIGHT LOWS BOTH DAYS WILL BE HELD UP BY LIGHT EASTERLY WINDS
AND ANY REMAINING MIDDLE AND HIGH CLOUD COVER FROM CONVECTION
EARLIER IN THE DAY/EVENING. CHURCH
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
EXTENDED PERIOD WILL BE IMPACTED BY AN UPPER LEVEL LOW OVER THE
PACIFIC NORTHWEST ON WEDNESDAY WHICH TRIES TO BEGIN MOVING BUT IS
OVER SOUTHERN SASKATCHEWAN BY SUNDAY. THIS SLOW MOVEMENT MEANS
THIS LOW WILL INFLUENCE THE WEATHER OVER MONTANA AND WYOMING BUT
ITS TRACK NORTH OF THE AREA MEANS ITS NOT STRONG FOR THE AREA
DYNAMICALLY BUT WILL GENERALLY KEEP CONVECTION IN THE FORECAST.
WEDNESDAY IS THE DAY FOR HIGHEST STRONG CONVECTION POTENTIAL AS AN
IMPULSE EJECTS AROUND THE LOW GIVING A NEGATIVE TILT TO THE FLOW
ALOFT. THE PATTERN ALSO ADVECTS IN SOME VERY WARM TEMPERATURES
ALOFT AND TRIES TO BRING A DRIER WESTERLY SURFACE FLOW FOR THE
WESTERN ZONES. CAPPING AND DOWNSLOPE COULD ERODE ANY CONVECTIVE
THREAT...BUT CONVECTIVE PARAMETERS ARE VERY HIGH WITH CAPES
PROGGED AROUND 2000-3000 J/KG AND DECENT LOW LEVEL SHEAR. BOTTOM
LINE...WEDNESDAY HAS SOLID UNCERTAINITY WITH IT AND COULD BE A
SIGNIFICANT SEVERE WEATHER DAY BUT AT THIS POINT IT IS EXPECTED
THAT GREATEST THREAT IS IN NORTHERN MONTANA.
WHAT HAS CHANGED IN THE MOST RECENT RUNS IS LOW DOES NOT EJECT AS
QUICKLY AS PREVIOUSLY INDICATED...WHICH GIVES A BETTER CHANCE FOR
THUNDER THURSDAY AND FRIDAY. TEMPERATURES WILL BE COOLER SO
THUNDER INTENSITY MAY NOT BE AS STRONG BUT UPPER LEVEL WINDS WILL
BE STRONGER SO SOME SHEAR IS AVAILABLE.
SATURDAY UPPER LOW AXIS CROSSES THE AREA AND THIS SHIFTS THE
MOISTURE NORTHEASTWARD AND IT DOES START LOOKING DRY SUNDAY INTO
MONDAY. TEMPERATURES WILL BE SEASONABLE AND AROUND 80 DEGREES.
BORSUM
&&
.AVIATION...
MOSTLY SUNNY CONDITIONS UNTIL AFTERNOON WITH MOUNTAIN CUMULUS
DEVELOPMENT. THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON AND
HAVE A BETTER CHANCE MOVING ONTO THE WESTERN AND CENTRAL PLAINS.
THUNDERSTORMS ARE POSSIBLE FOR KBIL...KLVM AND KSHR BY LATE
AFTERNOON INTO THE EVENING. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 080 058/086 061/086 056/077 050/076 050/075 051/074
2/T 22/T 24/T 42/T 33/T 22/T 22/T
LVM 081 047/085 053/083 049/072 040/073 042/074 047/076
3/T 34/T 33/T 33/T 33/T 22/T 23/T
HDN 080 056/088 056/089 058/078 053/077 050/076 051/075
2/T 12/T 23/T 33/T 33/T 22/T 22/T
MLS 079 057/087 061/088 062/081 055/077 055/077 055/077
1/U 11/U 23/T 33/T 33/T 33/T 33/T
4BQ 079 055/087 058/090 059/081 055/078 052/077 052/077
2/T 11/N 22/T 23/T 33/T 33/T 33/T
BHK 075 055/083 061/083 062/080 054/078 053/074 052/074
1/U 11/N 22/T 32/T 44/T 43/T 33/T
SHR 079 053/085 055/086 055/078 050/076 048/075 047/074
2/T 23/T 22/T 23/T 33/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 170251
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
851 PM MDT SUN JUN 16 2013
.UPDATE...
SOME HIGH-BASED SHOWERS AND STORMS HAVE BEEN MOVING OFF THE HIGHER
TERRAIN AND INTO THE NEARBY FOOTHILLS OF SOUTH CENTRAL MT OVER THE
LAST COUPLE HOURS. SO FAR...THIS ACTIVITY HAS DIED BEFORE REACHING
THE BILLINGS AREA...WHERE THE BOUNDARY LAYER IS CAPPED. WE DECIDED
TO LEAVE LOW /20 PERCENT/ POPS IN PLAY EVEN AT BILLINGS THROUGH 06
UTC THOUGH SINCE RECENT RADAR TRENDS SUGGEST AT LEAST THE REMNANTS
OF SHOWERS COULD AFFECT THE CITY. WE ALSO CHOSE TO ADD IN SOME LOW
POPS AFTER 06 UTC FROM THE BEARTOOTH/ABSAROKA MOUNTAINS TO BRIDGER
AND SHERIDAN. THAT IS BECAUSE THE SUBTLE MID-LEVEL SHORT WAVE THAT
HAS BEEN AIDING CONVECTION DIURNALLY WILL CONTINUE MOVING EAST AND
SOUTHEAST...AND WILL HAVE ACCESS TO ENOUGH ELEVATED INSTABILITY TO
PERHAPS KEEP A FEW SHOWERS OR WEAK STORMS GOING OVERNIGHT. SCHULTZ
&&
.SHORT TERM...VALID FOR MON AND TUE...
MOSTLY SUNNY SKIES WILL CONTINUE THROUGH THIS EVENING ACROSS THE
LOWER ELEVATIONS. CIRCULATION AROUND AN UPPER LOW ACROSS SOUTHERN
CANADA IS ALLOWING FOR AN UNSETTLED NORTHWEST FLOW ALOFT AND SOME
CUMULUS CLOUDS TO MOVE SOUTHEAST ACROSS OUR FAR NORTHEAST ZONES.
NOT EXPECTING ANY SHOWER ACTIVITY THESE CLOUDS AND EXPECT THESE
CLOUDS TO DISSIPATE SHORTLY AFTER SUNSET. HOWEVER...A WEAK
DISTURBANCE MOVING ACROSS EASTERN IDAHO AND NORTHWEST WYOMING WILL
RESULT IN A SLIGHT SHOWER/THUNDERSTORM CHANCE FOR THE
BEARTOOTH/ABSAROKA AND BIG HORN MOUNTAIN LOCATIONS THROUGH THIS
EVENING.
MONDAY & TUESDAY...ANOTHER UPPER LOW WILL SLOWLY MOVE ONTO THE
PACIFIC NORTHWEST COAST BRINGING A RETURNED SOUTHWEST FLOW ALOFT
TO OUR FORECAST AREA. HOWEVER...RIDGING AND RISING HEIGHTS WILL
FIRST BUILD ACROSS THE AREA MONDAY. A FEW WEAK DISTURBANCES MAY
UNDERCUT THE RIDGE MONDAY/MONDAY EVENING RESULTING IN A SLIGHT
SHOWER/THUNDERSTORM CHANCE MAINLY OVER THE MOUNTAINS AND FOOTHILL
LOCATIONS. THE RIDGE AXIS SLOWING SHIFTS EAST TUESDAY ALLOWING FOR
A RETURNED SOUTHWEST FLOW ALOFT TO THE FORECAST AREA. A FEW
DISTURBANCES WITHIN THE FLOW WILL MOVE OVERHEAD. THIS COMBINED
WITH A RETURNED EASTERLY SURFACE FLOW WILL ALLOW FOR BETTER
DYNAMICS FOR THUNDERSTORM ACTIVITY. AS A RESULT...CHANCES FOR A
THUNDERSTORM WILL EXIST ALONG AND WEST OF A BROADUS TO ROUNDUP
LINE TUESDAY AFTERNOON AND EVENING. AFTERNOON HIGHS MONDAY WILL BE
AT OR SLIGHTLY ABOVE NORMAL BUT AS 850MB TEMPERATURES WARM TO 25C-
28C TUESDAY READINGS WILL BE ABOUT 5 TO 10 DEGREES ABOVE NORMAL
WITH MOST LOCATIONS IN THE MIDDLE 80S. HOOLEY
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
WED THROUGH SAT...THE AREA IS UNDER SOUTHWESTERLY FLOW ALOFT
AHEAD OF A FAIRLY STATIONARY UPPER LEVEL LOW/TROUGH. THIS PATTERN
FAVORS PERIODS OF THUNDERSTORMS...ESPECIALLY AS SHORTWAVES SWING
THROUGH THE REGION...AND INTERACT WITH UPPER LEVEL JET
ENERGY/DIVERGENCE AND INSTABILITY. MOISTURE AVAILABILITY
CONTINUES TO BE THE BIG QUESTION. THE ECMWF KEEPS SURFACE
DEWPOINTS IN THE 50S TO LOW 60S ACROSS THE EASTERN HALF OF THE
REGION THROUGH THE EXTENDED...WHICH IS CERTAINLY SUFFICIENT FOR
HIGHER CAPE VALUES AND STRONGER STORMS...GIVEN MODEST CAPE VALUES.
WITH THE POTENTIAL FOR DEEPER LOW LEVEL MOISTURE ACROSS THE
EAST...SOME STORMS MAY PRODUCE HEAVY RAINS...INCREASING THE
POTENTIAL FOR FLASH FLOODING...PARTICULARLY IN BURN SCAR AREAS.
TIMING/STRENGTH OF SHORTWAVES WILL LIKELY DETERMINE WHEN/WHERE THE
STRONGEST STORMS WILL FIRE. AT THIS POINT...THERE IS TOO MUCH
UNCERTAINTY TO SAY EXACTLY WHEN/WHERE CONVECTION WILL FIRE...SO
MAINLY KEPT BROADBRUSHED SLIGHT CHANCE TO CHANCE POPS ACROSS THE
REGION.
DIFFERENCES IN THE EVOLUTION OF THE UPPER LEVEL LOW EXIST LATE
NEXT WEEKEND...WITH THE ECMWF BEGINNING TO MOVE IT NORTHEAST OF
THE REGION SUN AND THE GFS KEEPING IT MORE OR LESS IN PLACE OVER
MONTANA SUN. DUE TO THE MODEL DIFFERENCES...KEPT AT LEAST A SLIGHT
CHANCE OF POPS INTO SUN.
TEMPERATURES WILL BE WARMEST WEDNESDAY...WITH SOME CLOUD COVER
AND A FEW PERIODS OF WEAK COLD AIR ADVECTION BEHIND SHORTWAVES
KEEPING THE REST OF THE EXTENDED A BIT COOLER...PARTICULARLY
FRI INTO SAT. STC
&&
.AVIATION...
ISOLATED THUNDERSTORM ACTIVITY IS POSSIBLE INTO LATE THIS EVENING
OVER THE WESTERN AND SOUTHERN MOUNTAINS AND NEARBY FOOTHILLS.
STORMS MAY APPROACH KLVM...KBIL...AND KSHR THIS EVENING. VFR
CONDITIONS WILL PREVAIL FOR THE REST OF THE REGION. RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 052/080 056/086 058/086 054/075 050/074 050/073 051/074
21/B 12/T 24/T 42/T 33/T 22/T 22/T
LVM 044/081 047/085 050/083 047/070 040/071 042/072 047/076
21/B 23/T 23/T 33/T 33/T 22/T 23/T
HDN 051/080 056/088 054/089 056/076 053/075 050/074 051/075
11/U 12/T 23/T 33/T 33/T 22/T 22/T
MLS 051/079 057/087 060/088 060/079 055/075 055/075 055/077
01/U 11/U 23/T 33/T 33/T 33/T 33/T
4BQ 051/079 055/087 056/090 059/079 055/076 052/075 052/077
11/U 11/U 22/T 23/T 33/T 33/T 33/T
BHK 049/075 055/083 059/083 060/078 054/076 053/072 052/074
11/U 11/U 22/T 23/T 44/T 43/T 33/T
SHR 049/079 053/085 053/086 053/076 050/074 048/073 047/074
22/T 23/T 22/T 23/T 33/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 162324
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
524 PM MDT SUN JUN 16 2013
.UPDATE...
WE UPDATED THE FORECAST TO BRING ISOLATED TO SCATTERED SHOWERS AND
STORMS INTO THE PICTURE OVER THE LOWER ELEVATIONS AS FAR NORTH AND
EAST AS LIVINGSTON...BILLINGS...AND LODGE GRASS THIS EVENING. POPS
ARE IN THE 20 TO 30 PERCENT RANGE IN THOSE AREAS. AT 2315 UTC...WE
ARE STARTING TO SEE SOME OF THE HIGH-BASED CONVECTION FORMING OVER
THE MOUNTAINS SURVIVING THE TRIP OFF THE HIGHER TERRAIN. RAP-BASED
OBJECTIVE ANALYSIS DATA SUGGESTS MLCAPE OF 250 TO 500 J/KG FOR THE
ACTIVITY TO UTILIZE. IT DOES APPEAR THAT THE BOUNDARY LAYER AROUND
BILLINGS IS CAPPED...BUT VISUAL OBSERVATIONS REVEAL THE CONVECTIVE
TOWERS ARE ROBUST AND CLOSE ENOUGH TO WARRANT ISOLATED SHOWERS AND
STORMS IN THE FORECAST EVEN HERE FOR THE NEXT FEW HOURS. SCHULTZ
&&
.SHORT TERM...VALID FOR MON AND TUE...
MOSTLY SUNNY SKIES WILL CONTINUE THROUGH THIS EVENING ACROSS THE
LOWER ELEVATIONS. CIRCULATION AROUND AN UPPER LOW ACROSS SOUTHERN
CANADA IS ALLOWING FOR AN UNSETTLED NORTHWEST FLOW ALOFT AND SOME
CUMULUS CLOUDS TO MOVE SOUTHEAST ACROSS OUR FAR NORTHEAST ZONES.
NOT EXPECTING ANY SHOWER ACTIVITY THESE CLOUDS AND EXPECT THESE
CLOUDS TO DISSIPATE SHORTLY AFTER SUNSET. HOWEVER...A WEAK
DISTURBANCE MOVING ACROSS EASTERN IDAHO AND NORTHWEST WYOMING WILL
RESULT IN A SLIGHT SHOWER/THUNDERSTORM CHANCE FOR THE
BEARTOOTH/ABSAROKA AND BIG HORN MOUNTAIN LOCATIONS THROUGH THIS
EVENING.
MONDAY & TUESDAY...ANOTHER UPPER LOW WILL SLOWLY MOVE ONTO THE
PACIFIC NORTHWEST COAST BRINGING A RETURNED SOUTHWEST FLOW ALOFT
TO OUR FORECAST AREA. HOWEVER...RIDGING AND RISING HEIGHTS WILL
FIRST BUILD ACROSS THE AREA MONDAY. A FEW WEAK DISTURBANCES MAY
UNDERCUT THE RIDGE MONDAY/MONDAY EVENING RESULTING IN A SLIGHT
SHOWER/THUNDERSTORM CHANCE MAINLY OVER THE MOUNTAINS AND FOOTHILL
LOCATIONS. THE RIDGE AXIS SLOWING SHIFTS EAST TUESDAY ALLOWING FOR
A RETURNED SOUTHWEST FLOW ALOFT TO THE FORECAST AREA. A FEW
DISTURBANCES WITHIN THE FLOW WILL MOVE OVERHEAD. THIS COMBINED
WITH A RETURNED EASTERLY SURFACE FLOW WILL ALLOW FOR BETTER
DYNAMICS FOR THUNDERSTORM ACTIVITY. AS A RESULT...CHANCES FOR A
THUNDERSTORM WILL EXIST ALONG AND WEST OF A BROADUS TO ROUNDUP
LINE TUESDAY AFTERNOON AND EVENING. AFTERNOON HIGHS MONDAY WILL BE
AT OR SLIGHTLY ABOVE NORMAL BUT AS 850MB TEMPERATURES WARM TO 25C-
28C TUESDAY READINGS WILL BE ABOUT 5 TO 10 DEGREES ABOVE NORMAL
WITH MOST LOCATIONS IN THE MIDDLE 80S. HOOLEY
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
WED THROUGH SAT...THE AREA IS UNDER SOUTHWESTERLY FLOW ALOFT
AHEAD OF A FAIRLY STATIONARY UPPER LEVEL LOW/TROUGH. THIS PATTERN
FAVORS PERIODS OF THUNDERSTORMS...ESPECIALLY AS SHORTWAVES SWING
THROUGH THE REGION...AND INTERACT WITH UPPER LEVEL JET
ENERGY/DIVERGENCE AND INSTABILITY. MOISTURE AVAILABILITY
CONTINUES TO BE THE BIG QUESTION. THE ECMWF KEEPS SURFACE
DEWPOINTS IN THE 50S TO LOW 60S ACROSS THE EASTERN HALF OF THE
REGION THROUGH THE EXTENDED...WHICH IS CERTAINLY SUFFICIENT FOR
HIGHER CAPE VALUES AND STRONGER STORMS...GIVEN MODEST CAPE VALUES.
WITH THE POTENTIAL FOR DEEPER LOW LEVEL MOISTURE ACROSS THE
EAST...SOME STORMS MAY PRODUCE HEAVY RAINS...INCREASING THE
POTENTIAL FOR FLASH FLOODING...PARTICULARLY IN BURN SCAR AREAS.
TIMING/STRENGTH OF SHORTWAVES WILL LIKELY DETERMINE WHEN/WHERE THE
STRONGEST STORMS WILL FIRE. AT THIS POINT...THERE IS TOO MUCH
UNCERTAINTY TO SAY EXACTLY WHEN/WHERE CONVECTION WILL FIRE...SO
MAINLY KEPT BROADBRUSHED SLIGHT CHANCE TO CHANCE POPS ACROSS THE
REGION.
DIFFERENCES IN THE EVOLUTION OF THE UPPER LEVEL LOW EXIST LATE
NEXT WEEKEND...WITH THE ECMWF BEGINNING TO MOVE IT NORTHEAST OF
THE REGION SUN AND THE GFS KEEPING IT MORE OR LESS IN PLACE OVER
MONTANA SUN. DUE TO THE MODEL DIFFERENCES...KEPT AT LEAST A SLIGHT
CHANCE OF POPS INTO SUN.
TEMPERATURES WILL BE WARMEST WEDNESDAY...WITH SOME CLOUD COVER
AND A FEW PERIODS OF WEAK COLD AIR ADVECTION BEHIND SHORTWAVES
KEEPING THE REST OF THE EXTENDED A BIT COOLER...PARTICULARLY
FRI INTO SAT. STC
&&
.AVIATION...
ISOLATED THUNDERSTORM ACTIVITY IS POSSIBLE LATE THIS AFTERNOON
INTO LATE THIS EVENING OVER THE WESTERN AND SOUTHERN
MOUNTAINS/FOOTHILLS. STORMS MAY APPROACH KLVM...KBIL...AND KSHR
THIS EVENING. OUTSIDE OF ANY THUNDERSTORM...VFR CONDITIONS ARE
EXPECTED. STC
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 053/080 056/086 058/086 054/075 050/074 050/073 051/074
21/B 12/T 24/T 42/T 33/T 22/T 22/T
LVM 044/081 047/085 050/083 047/070 040/071 042/072 047/076
21/B 23/T 23/T 33/T 33/T 22/T 23/T
HDN 051/080 056/088 054/089 056/076 053/075 050/074 051/075
11/U 12/T 23/T 33/T 33/T 22/T 22/T
MLS 051/079 057/087 060/088 060/079 055/075 055/075 055/077
11/U 11/U 23/T 33/T 33/T 33/T 33/T
4BQ 051/079 055/087 056/090 059/079 055/076 052/075 052/077
11/U 11/U 22/T 23/T 33/T 33/T 33/T
BHK 050/075 055/083 059/083 060/078 054/076 053/072 052/074
11/U 11/U 22/T 23/T 44/T 43/T 33/T
SHR 049/079 053/085 053/086 053/076 050/074 048/073 047/074
22/T 23/T 22/T 23/T 33/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 162142
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
342 PM MDT SUN JUN 16 2013
.SHORT TERM...VALID FOR MON AND TUE...
MOSTLY SUNNY SKIES WILL CONTINUE THROUGH THIS EVENING ACROSS THE
LOWER ELEVATIONS. CIRCULATION AROUND AN UPPER LOW ACROSS SOUTHERN
CANADA IS ALLOWING FOR AN UNSETTLED NORTHWEST FLOW ALOFT AND SOME
CUMULUS CLOUDS TO MOVE SOUTHEAST ACROSS OUR FAR NORTHEAST ZONES.
NOT EXPECTING ANY SHOWER ACTIVITY THESE CLOUDS AND EXPECT THESE
CLOUDS TO DISSIPATE SHORTLY AFTER SUNSET. HOWEVER...A WEAK
DISTURBANCE MOVING ACROSS EASTERN IDAHO AND NORTHWEST WYOMING WILL
RESULT IN A SLIGHT SHOWER/THUNDERSTORM CHANCE FOR THE
BEARTOOTH/ABSAROKA AND BIG HORN MOUNTAIN LOCATIONS THROUGH THIS
EVENING.
MONDAY & TUESDAY...ANOTHER UPPER LOW WILL SLOWLY MOVE ONTO THE
PACIFIC NORTHWEST COAST BRINGING A RETURNED SOUTHWEST FLOW ALOFT
TO OUR FORECAST AREA. HOWEVER...RIDGING AND RISING HEIGHTS WILL
FIRST BUILD ACROSS THE AREA MONDAY. A FEW WEAK DISTURBANCES MAY
UNDERCUT THE RIDGE MONDAY/MONDAY EVENING RESULTING IN A SLIGHT
SHOWER/THUNDERSTORM CHANCE MAINLY OVER THE MOUNTAINS AND FOOTHILL
LOCATIONS. THE RIDGE AXIS SLOWLY SHIFTS EAST TUESDAY ALLOWING FOR
A RETURNED SOUTHWEST FLOW ALOFT TO THE FORECAST AREA. A FEW
DISTURBANCES WITHIN THE FLOW WILL MOVE OVERHEAD. THIS COMBINED
WITH A RETURNED EASTERLY SURFACE FLOW WILL ALLOW FOR BETTER
DYNAMICS FOR THUNDERSTORM ACTIVITY. AS A RESULT...CHANCES FOR A
THUNDERSTORM WILL EXIST ALONG AND WEST OF A BROADUS TO ROUNDUP
LINE TUESDAY AFTERNOON AND EVENING. AFTERNOON HIGHS MONDAY WILL BE
AT OR SLIGHTLY ABOVE NORMAL BUT AS 850MB TEMPERATURES WARM TO 25C-
28C TUESDAY READINGS WILL BE ABOUT 5 TO 10 DEGREES ABOVE NORMAL
WITH MOST LOCATIONS IN THE MIDDLE 80S. HOOLEY
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
WED THROUGH SAT...THE AREA IS UNDER SOUTHWESTERLY FLOW ALOFT
AHEAD OF A FAIRLY STATIONARY UPPER LEVEL LOW/TROUGH. THIS PATTERN
FAVORS PERIODS OF THUNDERSTORMS...ESPECIALLY AS SHORTWAVES SWING
THROUGH THE REGION...AND INTERACT WITH UPPER LEVEL JET
ENERGY/DIVERGENCE AND INSTABILITY. MOISTURE AVAILABILITY
CONTINUES TO BE THE BIG QUESTION. THE ECMWF KEEPS SURFACE
DEWPOINTS IN THE 50S TO LOW 60S ACROSS THE EASTERN HALF OF THE
REGION THROUGH THE EXTENDED...WHICH IS CERTAINLY SUFFICIENT FOR
HIGHER CAPE VALUES AND STRONGER STORMS...GIVEN MODEST CAPE VALUES.
WITH THE POTENTIAL FOR DEEPER LOW LEVEL MOISTURE ACROSS THE
EAST...SOME STORMS MAY PRODUCE HEAVY RAINS...INCREASING THE
POTENTIAL FOR FLASH FLOODING...PARTICULARLY IN BURN SCAR AREAS.
TIMING/STRENGTH OF SHORTWAVES WILL LIKELY DETERMINE WHEN/WHERE THE
STRONGEST STORMS WILL FIRE. AT THIS POINT...THERE IS TOO MUCH
UNCERTAINTY TO SAY EXACTLY WHEN/WHERE CONVECTION WILL FIRE...SO
MAINLY KEPT BROADBRUSHED SLIGHT CHANCE TO CHANCE POPS ACROSS THE
REGION.
DIFFERENCES IN THE EVOLUTION OF THE UPPER LEVEL LOW EXIST LATE
NEXT WEEKEND...WITH THE ECMWF BEGINNING TO MOVE IT NORTHEAST OF
THE REGION SUN AND THE GFS KEEPING IT MORE OR LESS IN PLACE OVER
MONTANA SUN. DUE TO THE MODEL DIFFERENCES...KEPT AT LEAST A SLIGHT
CHANCE OF POPS INTO SUN.
TEMPERATURES WILL BE WARMEST WEDNESDAY...WITH SOME CLOUD COVER
AND A FEW PERIODS OF WEAK COLD AIR ADVECTION BEHIND SHORTWAVES
KEEPING THE REST OF THE EXTENDED A BIT COOLER...PARTICULARLY
FRI INTO SAT. STC
&&
.AVIATION...
ISOLATED THUNDERSTORM ACTIVITY IS POSSIBLE LATE THIS AFTERNOON
INTO LATE THIS EVENING OVER THE WESTERN AND SOUTHERN
MOUNTAINS/FOOTHILLS. STORMS MAY APPROACH KLVM...KBIL...AND KSHR
THIS EVENING. OUTSIDE OF ANY THUNDERSTORM...VFR CONDITIONS ARE
EXPECTED. STC
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 053/080 056/086 058/086 054/075 050/074 050/073 051/074
11/B 12/T 24/T 42/T 33/T 22/T 22/T
LVM 044/081 047/085 050/083 047/070 040/071 042/072 047/076
11/B 23/T 23/T 33/T 33/T 22/T 23/T
HDN 051/080 056/088 054/089 056/076 053/075 050/074 051/075
01/U 12/T 23/T 33/T 33/T 22/T 22/T
MLS 051/079 057/087 060/088 060/079 055/075 055/075 055/077
01/U 11/U 23/T 33/T 33/T 33/T 33/T
4BQ 051/079 055/087 056/090 059/079 055/076 052/075 052/077
11/U 11/U 22/T 23/T 33/T 33/T 33/T
BHK 050/075 055/083 059/083 060/078 054/076 053/072 052/074
11/U 11/U 22/T 23/T 44/T 43/T 33/T
SHR 049/079 053/085 053/086 053/076 050/074 048/073 047/074
22/T 23/T 22/T 23/T 33/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 161506
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
906 AM MDT SUN JUN 16 2013
.UPDATE...
SUNNY SKIES ON TAP ONCE AGAIN TODAY WITH TEMPERATURES AROUND
NORMAL FOR THIS TIME OF YEAR. THERE WILL BE A SLIGHT CHANCE FOR A
THUNDERSTORM OVER THE MOUNTAINS AND ADJACENT FOOTHILLS THIS
AFTERNOON. CURRENT FORECAST IN GOOD SHAPE WITH NO UPDATES PLANNED.
HOOLEY
&&
.SHORT TERM...VALID FOR TDY AND MON...
A PLEASANT FATHERS DAY IS ON TAP TODAY...WITH SEASONAL
TEMPERATURES AND DRY CONDITIONS OVER MUCH OF THE FORECAST AREA.
THE ONLY EXCEPTION TO THE DRY CONDITIONS WILL BE OVER THE
MOUNTAINS WHERE INCREASING MID-LEVEL MOISTURE...DIURNAL HEATING
AND OROGRAPHIC LIFT SHOULD BE ENOUGH TO DEVELOP SOME LATE
AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS. FOR THE REST OF THE
FORECAST AREA...A WEAK BACKDOOR COLD FRONT WILL SWITCH WINDS
AROUND TO THE NORTH AND EAST BY THE AFTERNOON. SENSIBLE IMPACTS
FROM THIS FRONT WILL BE LIMITED TO THE WIND DIRECTION AS SKIES
WILL REMAIN CLEAR AND TEMPERATURES ON PAR WITH YESTERDAY.
THE BEGINNING OF A LOW-LEVEL EASTERLY FLOW REGIME WILL ESTABLISH
BY MONDAY...BRINGING A SLOW INCREASE OF LOW-LEVEL MOISTURE INTO
THE FORECAST AREA. MUCH OF THIS GULF FEED OF MOISTURE WILL STAY
SOUTH OF THE FORECAST AREA ON MONDAY...BUT WITH DEW POINTS
EXPECTED TO BE AROUND 50 WITH TEMPERATURES NEAR 80 CANNOT RULE OUT
SOME SCATTERED ISOLATED SHOWERS AND THUNDERSTORMS MOVING OFF THE
MOUNTAINS INTO THE NEARBY FOOTHILLS BY THE LATE AFTERNOON. CHURCH
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
TUESDAY THROUGH FRIDAY THE AREA IS UNDER SOUTHWESTERLY FLOW ALOFT
WHICH HAS PULSES OF ENERGY SWINGING ACROSS THE AREA. THIS IS A
PATTERN FAVORABLE FOR THUNDERSTORMS BUT MOISTURE AVAILABILITY IS
THE BIG QUESTIONS. THERE APPEARS TO BE NO MIDLEVEL SUBTROPICAL
MOISTURE FOR THE UPPER FLOW TO WORK WITH SO DEPTH OF RETURN FLOW
MOISTURE UP THE PLAINS WILL DICTATE CHANCES OF THUNDER. MODELS
WANT TO PULL JUST ENOUGH MOISTURE UP TO THE MOUNTAINS TO KEEP A
RISK OF THUNDER IN THE FORECAST ACROSS THE AREA BUT EXPECT ONLY A
HANDFUL OF STORMS TO DEVELOP EACH PERIOD. BETTER CAPE WILL EXIST
OVER EASTERN MONTANA DURING NIGHTTIME PERIODS SO WILL HAVE TO
WATCH FOR STRONGER THUNDERSTORMS BUT NOT ENOUGH CONFIDENCE TO
PROMINENTLY MENTION AT THIS TIME.
UPPER LOW EJECTS EASTWARD FOR THE WEEKEND WHICH WILL SHIFT LOW
LEVEL MOISTURE OUT OF THE REGION AND FURTHER REDUCE THUNDER
CHANCES.
TEMPERATURES WILL BE WARMEST TUESDAY AND WEDNESDAY BEFORE LOWER
HEIGHTS MOVE INTO THE AREA AND HIGHS WILL BACK TO NORMAL LEVELS.
BORSUM
&&
.AVIATION...
MOSTLY CLEAR CONDITIONS WILL GIVE WAY TO INCREASING MID/HIGH
CLOUDS IN THE AFTERNOON. ISOLATED THUNDERSTORM ACTIVITY IS
POSSIBLE LATE THIS AFTERNOON INTO THIS EVENING OVER THE WESTERN
MOUNTAINS/FOOTHILLS. STC
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 079 053/080 057/085 054/086 054/075 049/074 050/073
0/U 11/B 12/T 23/T 32/T 33/T 22/T
LVM 080 044/081 047/084 048/083 047/070 039/071 042/072
1/U 11/B 23/T 23/T 33/T 22/T 23/T
HDN 081 051/080 056/088 054/090 056/076 052/075 050/074
0/U 01/U 12/T 22/T 22/T 33/T 22/T
MLS 080 052/079 057/086 058/087 060/079 054/075 055/075
1/U 01/U 11/U 12/T 33/T 33/T 23/T
4BQ 081 051/079 055/087 056/089 059/079 054/076 052/075
1/U 11/U 12/T 22/T 22/T 33/T 22/T
BHK 077 048/075 055/083 057/082 060/078 053/076 053/072
1/U 11/U 11/U 12/T 22/T 33/T 33/T
SHR 079 049/079 053/085 051/087 053/076 049/074 048/073
1/U 12/T 23/T 22/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 160843
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
243 AM MDT SUN JUN 16 2013
.SHORT TERM...VALID FOR TDY AND MON...
A PLEASANT FATHERS DAY IS ON TAP TODAY...WITH SEASONAL
TEMPERATURES AND DRY CONDITIONS OVER MUCH OF THE FORECAST AREA.
THE ONLY EXCEPTION TO THE DRY CONDITIONS WILL BE OVER THE
MOUNTAINS WHERE INCREASING MID-LEVEL MOISTURE...DIURNAL HEATING
AND OROGRAPHIC LIFT SHOULD BE ENOUGH TO DEVELOP SOME LATE
AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS. FOR THE REST OF THE
FORECAST AREA...A WEAK BACKDOOR COLD FRONT WILL SWITCH WINDS
AROUND TO THE NORTH AND EAST BY THE AFTERNOON. SENSIBLE IMPACTS
FROM THIS FRONT WILL BE LIMITED TO THE WIND DIRECTION AS SKIES
WILL REMAIN CLEAR AND TEMPERATURES ON PAR WITH YESTERDAY.
THE BEGINNING OF A LOW-LEVEL EASTERLY FLOW REGIME WILL ESTABLISH
BY MONDAY...BRINGING A SLOW INCREASE OF LOW-LEVEL MOISTURE INTO
THE FORECAST AREA. MUCH OF THIS GULF FEED OF MOISTURE WILL STAY
SOUTH OF THE FORECAST AREA ON MONDAY...BUT WITH DEW POINTS
EXPECTED TO BE AROUND 50 WITH TEMPERATURES NEAR 80 CANNOT RULE OUT
SOME SCATTERED ISOLATED SHOWERS AND THUNDERSTORMS MOVING OFF THE
MOUNTAINS INTO THE NEARBY FOOTHILLS BY THE LATE AFTERNOON. CHURCH
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
TUESDAY THROUGH FRIDAY THE AREA IS UNDER SOUTHWESTERLY FLOW ALOFT
WHICH HAS PULSES OF ENERGY SWINGING ACROSS THE AREA. THIS IS A
PATTERN FAVORABLE FOR THUNDERSTORMS BUT MOISTURE AVAILABILITY IS
THE BIG QUESTIONS. THERE APPEARS TO BE NO MIDLEVEL SUBTROPICAL
MOISTURE FOR THE UPPER FLOW TO WORK WITH SO DEPTH OF RETURN FLOW
MOISTURE UP THE PLAINS WILL DICTATE CHANCES OF THUNDER. MODELS
WANT TO PULL JUST ENOUGH MOISTURE UP TO THE MOUNTAINS TO KEEP A
RISK OF THUNDER IN THE FORECAST ACROSS THE AREA BUT EXPECT ONLY A
HANDFUL OF STORMS TO DEVELOP EACH PERIOD. BETTER CAPE WILL EXIST
OVER EASTERN MONTANA DURING NIGHTTIME PERIODS SO WILL HAVE TO
WATCH FOR STRONGER THUNDERSTORMS BUT NOT ENOUGH CONFIDENCE TO
PROMINENTLY MENTION AT THIS TIME.
UPPER LOW EJECTS EASTWARD FOR THE WEEKEND WHICH WILL SHIFT LOW
LEVEL MOISTURE OUT OF THE REGION AND FURTHER REDUCE THUNDER
CHANCES.
TEMPERATURES WILL BE WARMEST TUESDAY AND WEDNESDAY BEFORE LOWER
HEIGHTS MOVE INTO THE AREA AND HIGHS WILL BACK TO NORMAL LEVELS.
BORSUM
&&
.AVIATION...
MOSTLY CLEAR CONDITIONS WILL GIVE WAY TO INCREASING HIGH CLOUDS IN
THE AFTERNOON. ISOLATED THUNDERSTORM ACTIVITY IS POSSIBLE BY LATE
AFTERNOON OVER THE HIGHER MOUNTAINS BUT THE PLAINS WILL REMAIN
DRY. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 079 053/080 057/085 054/086 054/075 049/074 050/073
0/U 11/B 12/T 23/T 32/T 33/T 22/T
LVM 080 044/081 047/084 048/083 047/070 039/071 042/072
1/U 11/B 23/T 23/T 33/T 22/T 23/T
HDN 081 051/080 056/088 054/090 056/076 052/075 050/074
0/U 01/U 12/T 22/T 22/T 33/T 22/T
MLS 080 052/079 057/086 058/087 060/079 054/075 055/075
1/U 01/U 11/U 12/T 33/T 33/T 23/T
4BQ 081 051/079 055/087 056/089 059/079 054/076 052/075
1/U 11/U 12/T 22/T 22/T 33/T 22/T
BHK 077 048/075 055/083 057/082 060/078 053/076 053/072
1/U 11/U 11/U 12/T 22/T 33/T 33/T
SHR 079 049/079 053/085 051/087 053/076 049/074 048/073
1/U 12/T 23/T 22/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
000
FXUS65 KBYZ 160242
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
842 PM MDT SAT JUN 15 2013
.UPDATE...
A WEAK COOL FRONT IS MOVING SOUTH ACROSS THE AREA THIS EVENING AND
CAN BE SEEN ON RADAR AS A FINE-LINE IN BASE REFLECTIVITY IMAGES TO
THE NORTHEAST OF BILLINGS AT 0230 UTC. WINDS WILL BECOME NORTHERLY
BEHIND THE FRONT...BUT THE SURFACE GRADIENT IS WEAK ENOUGH THAT IT
MAY BE DIFFICULT TO PICK OUT THE EFFECTS OF THE FRONT AFTER 06 UTC
WHEN SOME LIGHT DRAINAGE EFFECTS TAKE OVER WINDS IN SOME SPOTS. WE
DID BLEND THE GRIDDED WIND FORECASTS TO RECENT LAMP AND RUC OUTPUT
TO HELP CAPTURE THIS SCENARIO. OTHERWISE...WE LOWERED TEMPERATURES
JUST SLIGHTLY IN A FEW PLACES...ESPECIALLY AROUND LIVINGSTON WHERE
EVENING DEWPOINTS ARE RUNNING IN THE MID 30S F. SCHULTZ
&&
.SHORT TERM...VALID FOR SUN AND MON...
A SUNNY TO MOSTLY SUNNY WEEKEND REMAINS ON TAP ACROSS OUR
FORECAST AREA ALONG WITH SEASONAL TEMPERATURES. UPPER LOW
CONTINUES TO SLOWLY MOVE EAST AND SOUTHEAST ACROSS SOUTHERN CANADA
INTO NORTH DAKOTA AND MINNESOTA LEAVING MOSTLY CLEAR SKIES FOR OUR
AREA. SUBSIDENCE ACROSS SOUTHERN MONTANA IS RESULTING IN A MOSTLY
SUNNY DAY BUT COLD AIR ALOFT COMBINED WITH A WEAK COLD FRONT
ACROSS THE NORTHEASTERN PORTIONS OF THE STATE HAS RESULTED IN
QUITE A BIT OF CUMULUS ACROSS THAT AREA. THIS FRONT WILL SLIDE
SOUTH THIS EVENING AND OVERNIGHT BRINGING A WIND SHIFT TO THE
NORTHEAST LATE TONIGHT AND THROUGH THE DAY SUNDAY.
HOWEVER...ATMOSPHERE REMAINS DRY SO NOT EXPECTING ANY PRECIP WITH
THE FRONT. A FEW CLOUDS WILL POSSIBLY WORK THEIR WAY SOUTH INTO
OUR FAR NORTH AND NORTHEAST ZONES BUT THESE ARE EXPECTED TO
DISSIPATE SHORTLY AFTER SUNSET. TEMPERATURES WILL BE A FEW DEGREES
WARMER TONIGHT FOR SOME AREAS BUT STILL EXPECT A CHILLY NIGHT ONCE
AGAIN WITH TEMPERATURES SLIGHTLY BELOW NORMAL.
HIGH PRESSURE RIDGING BEGINS TO BUILD ALONG WITH RISING HEIGHTS
SUNDAY AND ESPECIALLY INTO MONDAY. A FEW WEAK DISTURBANCES MAY
UNDERCUT THE RIDGE RESULTING IN A SLIGHT SHOWER/THUNDERSTORM
CHANCE MAINLY OVER THE MOUNTAINS AND NEARBY FOOTHILLS BOTH SUNDAY
AND MONDAY AFTERNOON/EVENING. HIGH TEMPERATURES SUNDAY WILL BE
AROUND AVERAGE WITH MIDDLE TO UPPER 70S WITH READINGS A FEW
DEGREES WARMER ON MONDAY. HOOLEY
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
RIDGING BEGINS BREAKING DOWN LATE TUES AS UPPER LEVEL FLOW BECOMES
INCREASINGLY SOUTHWESTERLY. SHORTWAVES EMBEDDED WITHIN THE FLOW
WILL WORK WITH SURFACE DEWPOINTS IN THE 40S TO LOW 50S...A BIT OF
SHEAR...AND DAYTIME INSTABILITY TO INCREASE CHANCES OF SHOWERS
AND THUNDERSTORMS ACROSS WESTERN AND CENTRAL AREAS...AS FAR EAST
AS BILLINGS AND SHERIDAN. FOR NOW...KEPT POPS LOW THROUGH TUES
EVE...BUT IF SHORTWAVE ACTIVITY LOOKS STRONGER AS TUES
APPROACHES...WE WILL NEED TO RAISE POPS. HIGH TEMPS WILL BE IN THE
80S.
MORE SHORTWAVE ACTIVITY IN SW FLOW ALOFT IS EXPECTED TO BRING
SHOWERS AND THUNDERSTORMS TO THE REGION WED...WITH THE BEST
CHANCES AGAIN ACROSS THE WEST AND CENTRAL WHERE STRONG UPPER LEVEL
JET ENERGY/DIVERGENCE WILL HELP TO DEEPEN A SURFACE
LOW AND INCREASE FRONTOGENETICAL AND LOW-LEVEL FORCING. SHEAR
LOOKS MARGINAL...BUT CAPE VALUES ARE QUITE HIGH WED AFTN/EVE...SO
NOT SURE ABOUT THE LIKELIHOOD OF SEVERE STORMS...BUT CERTAINLY
SOME STRONG STORMS ARE POSSIBLE. 700 MB TEMPS ACROSS THE EAST WED
AFTN/EVE WILL BE IN THE +12C TO +14C RANGE...WHICH MAY CAP THAT
REGION. SO...AT THIS POINT...LESS CONVECTIVE ACTIVITY IS EXPECTED
ACROSS THE EAST. WED NIGHT INTO THURS...THE SURFACE LOW MOVES
E...DRAGGING A COLD FRONT WITH IT. THIS WILL STABILIZE THE
ATMOSPHERE A BIT THROUGH A GOOD PORTION OF THURS. EXPECT HIGHS
AGAIN IN THE 80S ACROSS MUCH OF THE REGION WED...WITH HIGHS IN THE
70S THURS.
SHORTWAVE ENERGY ROUNDING THE BASE OF THE UPPER LEVEL TROUGH LATE
THURS INTO EARLY FRI WILL INCREASE UPPER LEVEL DIVERGENCE AND
POTENTIALLY HELP TO DEVELOP ANOTHER SURFACE LOW ACROSS SOUTHERN
MT/NORTHERN WY...SETTING THE STAGE FOR FURTHER CONVECTIVE
DEVELOPMENT ACROSS THE REGION. CONVECTION SHOULD FIRE OVER THE
WEST AND CENTRAL LATE THURS EVE...AND PROPAGATE EASTWARD THROUGH
THE OVERNIGHT HOURS AND INTO EARLY FRI AS THE LOW DRAGS ANOTHER
COLD FRONT THROUGH THE REGION. SHEAR VALUES LOOK SUFFICIENT FOR AT
LEAST STRONG STORMS LATE THURS INTO EARLY FRI MORNING...BUT LOW
LEVEL MOISTURE IS LOWER THAN WED...THUS CAPE VALUES ARE NOT ALL
THAT HIGH. WILL HAVE TO KEEP AN EYE ON SURFACE DEWPOINTS. IF THEY
RECOVER INTO THE 50S ACROSS THE EASTERN HALF OF THE REGION THURS
NIGHT...AS SUGGESTED BY THE ECMWF...THERE WILL BE A BETTER CHANCE
OF SOME STORMS BECOMING SEVERE.
FRI LOOKS TO BE A TOUCH COOLER THAN THURS ACROSS THE REGION
BEHIND THE FRONT WITH A MORE STABLE AIRMASS BUILDING
IN...ESPECIALLY BY LATER IN THE DAY. ANOTHER STRONG SHORTWAVE
TROUGH APPROACHES THE REGION SAT...INCREASING THE POTENTIAL FOR
SHOWERS AND THUNDERSTORMS. STC
&&
.AVIATION...
VFR CONDITIONS WITH NO FLIGHT HAZARDS TO AVIATION ARE EXPECTED
TONIGHT THROUGH MID DAY SUNDAY. A WEAK DISTURBANCE WILL BRING A
FEW THUNDERSTORMS OVER THE WESTERN MOUNTAINS BY MID AFTERNOON
SUNDAY. THE SHOWERS AND THUNDERSTORMS COULD CREATE A BRIEF PERIOD
OF MOUNTAIN OBSCURATIONS. THE PLAINS WILL REMAIN DRY. RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 049/077 053/080 057/085 054/086 054/075 049/074 050/073
00/U 11/B 12/T 23/T 32/T 33/T 22/T
LVM 037/078 044/081 047/084 048/083 047/070 039/071 042/072
01/U 11/B 22/T 23/T 33/T 22/T 23/T
HDN 048/079 051/080 056/088 054/090 056/076 052/075 050/074
00/U 01/U 12/T 22/T 22/T 33/T 22/T
MLS 051/078 052/079 057/086 058/087 060/079 054/075 055/075
01/U 01/U 11/U 12/T 33/T 33/T 23/T
4BQ 048/079 051/079 055/087 056/089 059/079 054/076 052/075
01/U 11/U 12/T 22/T 22/T 33/T 22/T
BHK 047/075 048/075 055/083 057/082 060/078 053/076 053/072
01/U 11/U 11/U 12/T 22/T 33/T 33/T
SHR 044/077 049/079 053/085 051/087 053/076 049/074 048/073
01/U 12/T 23/T 22/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
| 
