National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KBYZ 162129
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
329 PM MDT THU MAY 16 2013

.SHORT TERM...VALID FOR FRI AND SAT...

SHOWERS AND THUNDERSTORMS ARE DEVELOPING FROM ROUGHLY KBIL TO
KSHR WEST THIS AFTERNOON. THUS FAR NOTHING HAS BEEN SIGNIFICANTLY
STRONG...BUT HAS BEEN PRODUCING PLENTY OF LIGHTNING. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO CONTINUE THROUGH THE EVENING AND
MUCH OF THE OVERNIGHT AS THEY PROCEED EASTWARD.

SEASONAL TEMPERATURES AND UNSETTLED WEATHER ARE EXPECTED THROUGH
THE SHORT TERM PERIOD...AS PERSISTENT SOUTHWEST FLOW ALOFT CONTINUES
TO DOMINATE THE PATTERN AHEAD OF AN APPROACHING TROF. TEMPERATURES
IN THIS PATTERN WILL REMAIN AT OR ABOVE NORMAL FRIDAY AND
SATURDAY.

HAVE CONTINUED WITH CHANCE TO LIKELY POPS ACROSS THE REGION
THIS EVENING AND OVERNIGHT...PARING BACK EAST SLIGHTLY. IT DOES
LOOK LIKE THERE SHOULD BE A BREAK IN PRECIP THROUGH MUCH OF THIS
EVENING...WITH SOME SHORTWAVE RIDGING ...BUT ACTIVITY IS SEEMS TO
BE EXPANDING IN COVERAGE FAIRLY QUICKLY...AND MOVING EASTWARD AT A
GOOD CLIP AS WELL. DID NOT FEEL COMFORTABLE CLEARING OUT CHANCES
COMPLETELY IN THE EAST THROUGH THE REMAINDER OF THE
AFTERNOON...BUT APPEARS TO BE A LESSER CHANCE.

DIFFLUENCE ALOFT APPEARS TO BE IMPROVING FOR FRIDAY AND FRIDAY
NIGHT...LEADING TO CONTINUED HIGH CHANCE TO LIKELY POPS...WITH
MORE WIDESPREAD SHOWERS ACROSS THE REGION. ADDITIONALLY...EASTERN
ZONES...INCLUDING KMLS...KBHK...KEKA...AND K4BQ WILL SEE
POTENTIAL FOR SEVERE THUNDERSTORMS...MAINLY IN FORM OF LARGE
HAIL...AS DEWPOINTS IN THE 50S...CAPE AROUND 1500 J/KG...AND
STRONG SHEAR COMBINE IN THE AFTERNOON AND EVENING.

SATURDAY APPEARS TO BE THE WETTEST DAY OF THE PERIOD...AS INCREASED
UPPER LEVEL SUPPORT AND MID LEVEL ENERGY ALONG THE TROF AXIS PUSH
INTO THE REGION. HAVE INCREASED POPS...TO LIKELY IN MOST
AREAS...AND BUMPED QPF UPWARD AS WELL. CONTINUED TO CARRY A
MENTION OF THUNDERSTORMS...BUT NOTHING SEVERE IS EXPECTED. AAG

.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...

BROAD UPPER TROUGH OF LOW PRESSURE WILL REMAIN OVER THE NORTHERN
PLAINS THROUGH EARLY NEXT WEEK AND CREATE AN UNSETTLED WEATHER
PATTERN. UPPER LEVEL ENERGY WITH THIS TROUGH ALONG WITH Q VECTOR
FORCING AND JET DYNAMICS...WILL COMBINE TO BRING SCATTERED SHOWERS
AND THUNDERSTORMS TO THE ENTIRE REGION ON SUNDAY. PRECIPITATION
CHANCES SHOULD DIMINISH FROM THE WEST ON MONDAY AS THE UPPER LOW
MOVES SLOWLY AWAY FROM OUR AREA. ENERGY WRAPPING AROUND THE LOW
WILL CONTINUE TO BRING A CHANCE OF SHOWERS AND STORMS OVER
SOUTHEASTERN MONTANA ON MONDAY. TEMPERATURES SUNDAY AND MONDAY
WILL FALL TO SLIGHTLY BELOW SEASONAL NORMALS WITH THE LOWER
HEIGHTS. SHORT WAVE RIDGING TO DEVELOP OVER THE AREA TUESDAY
THROUGH EARLY WEDNESDAY FOR MAINLY DRY WEATHER AND A RETURN TO
ABOVE NORMAL TEMPERATURES. RIDGING WILL SHIFT QUICKLY EASTWARD BY
WEDNESDAY NIGHT AS ANOTHER TROUGH OF LOW PRESSURE MOVES IN FROM
THE WEST COAST...CAUSING FLOW ALOFT TO BACK TO THE SOUTHWEST AND
INCREASING DIFFLUENT FLOW ALOFT. MODELS ARE IN GOOD AGREEMENT WITH
DEVELOPING A CLOSED UPPER LEVEL LOW PRESSURE SYSTEM WITH THE
TROUGH. THIS WEATHER PATTERN IS USUALLY A GOOD PRECIP MAKER FOR
OUR AREA BUT THE MODELS ARE INDICATING VERY DRY AIR FROM THE
DESERT SOUTHWEST WILL BE ADVECTED INTO THE DEVELOPING SOUTHERLY
FLOW. NEWEST 12Z AND 18Z MODEL RUNS ARE INDICATING THAT THERE
MAYBE A MOISTURE TAP FROM THE GULF COAST AND THIS WOULD
SIGNIFICANTLY INCREASE OUR CHANCE FOR PRECIPITATION LATE NEXT
WEEK. WILL NEED TO SEE HOW FURTHER MODEL RUNS HANDLE THIS SYSTEM
DUE TO CURRENT INCONSISTENCIES. RICHMOND

&&

.AVIATION...

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO
DEVELOP THIS AFTERNOON AND EVENING. STORM WILL MOVE OFF THE
MOUNTAINS AND ACROSS THE PLAINS THIS EVENING. THE PRECIPITATION
COULD BRING MVFR TO IFR CONDITIONS IN AREAS WITH THE HEAVIEST
RAINFALL. OCCASIONAL MOUNTAIN OBSCURATION AND ALSO BE EXPECTED.
RICHMOND

&&

.PRELIMINARY POINT TEMP/POPS...

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 053/071 053/069 051/066 048/062 045/074 049/074 050/073
    56/T    66/T    65/T    54/T    31/B    12/T    21/B
LVM 046/065 043/067 044/063 040/060 038/067 043/074 040/069
    66/T    55/T    84/T    44/T    31/B    13/T    33/T
HDN 052/075 053/073 050/068 047/063 043/074 046/077 049/075
    55/T    66/T    65/T    55/T    41/B    12/T    21/B
MLS 052/076 055/072 052/068 049/064 046/072 046/075 050/073
    46/T    77/T    65/T    66/T    63/W    22/T    22/T
4BQ 051/079 054/075 049/067 047/061 043/065 044/076 049/073
    45/T    67/T    55/T    66/T    63/W    11/B    11/B
BHK 048/075 053/074 050/067 047/061 043/063 043/072 049/069
    56/T    77/T    65/T    56/T    64/W    21/B    22/T
SHR 048/075 048/070 045/065 043/058 039/066 040/077 047/074
    53/T    55/T    55/T    66/T    42/W    12/T    21/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

&&

$$
WEATHER.GOV/BILLINGS