Area Forecast Discussion
Issued by NWS Billings, MT

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000
FXUS65 KBYZ 250929
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
329 AM MDT SAT JUL 25 2015

.SHORT TERM...VALID FOR TDY AND SUN...

NOT MUCH CHANGE IN THE WEATHER PATTERN EXPECTED TODAY THROUGH
SUNDAY. CURRENTLY...THE TAIL END OF A 70KT JET MOVING NORTHEAST
THROUGH CENTRAL WYOMING INTO SOUTH DAKOTA HAS RESULTED IN THE
DEVELOPMENT OF A CLUSTER OF STRONG THUNDERSTORMS ACROSS NORTHEAST
WYOMING. A FEW OF THESE STORMS HAVE CROSSED INTO CARTER COUNTY BUT
THEY ARE EXPECTED TO BE OUT OF THE AREA WITHIN THE NEXT HOUR OR
TWO.

THE FOCUS THEN SHIFTS TO A LARGE UPPER LOW AND TROUGH MOVING ONTO
THE BRITISH COLUMBIA COAST TODAY...THEN SOUTHWARD ACROSS THE
PACIFIC NORTHWEST COAST DURING THE DAY SUNDAY. THIS WILL RESULT
IN AN INCREASING SOUTHWEST FLOW ALOFT TODAY THROUGH SUNDAY. A FEW
DISTURBANCES AGAIN WILL MOVE THROUGH THE FLOW ALLOWING FOR AN
ISOLATED CHANCE FOR A SHOWER OR THUNDERSTORM...MAINLY DURING THE
AFTERNOON AND EVENING BOTH DAYS. AN ISOLATED STRONG THUNDERSTORM
WILL BE POSSIBLE THIS AFTERNOON/EVENING ACROSS OUR FAR EAST NEAR
THE DAKOTA BORDERS WHERE SHEAR IS BEST AND A SURFACE TROUGH IS
LOCATED. PRECIPITAL WATERS WILL MAINLY BE IN THE 0.75-1.00" RANGE
SO HEAVY RAIN WILL BE LIKELY WITH ANY THUNDERSTORM. TEMPERATURES
WILL CONTINUE TO BE VERY WARM AND ABOVE NORMAL WITH READINGS IN
THE LOWER 90S FOR MOST AREAS. HOOLEY

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

UNSEASONABLY DEEP WAVE EXPECTED TO MOVE FROM EASTERN OREGON TO
SOUTHWEST SASKATCHEWAN DURING THE FIRST 24 HOURS FOLLOWED BY A
WINDY TUESDAY AND THEN A MUCH QUIETER EXTENDED PERIOD. 00Z GFS
TOOK A BIG JUMP ON MONDAY TRACK BUT NEW ECMWF FOLLOWED THIS TREND
SO REASONABLY CONFIDENT ON SURFACE LOW POSITIONING.

ON MONDAY CYCLOGENESIS PROGGED ALONG THE MONTANA DAKOTA BORDER
WITH SURFACE FRONT PROGGED TO MOVE FROM KBZN AT 18Z TO JUST EAST
OF KBIL AT 00Z AND THEN WELL INTO THE DAKOTAS BY 06Z. TEMPERATURES
ON MONDAY IN THE CENTRAL SECTIONS DEPENDENT OF FRONTAL TIMING BUT
WESTERN AREAS SHOULD SEE BELOW NORMAL TEMPERATURES WHILE IT WILL
BE HOT ACROSS THE EAST. THE SURFACE LOW POSITION LOOKS TO KEEP THE
HIGHEST PRECIPITABLE WATERS NORTH OF THE AREA SO THUNDERSTORM
CHANCES ARE LIMITED BUT WITH SUCH A DYNAMIC SYSTEM A FEW STORMS
CANNOT BE RULED OUT WITH MUCH DEEPER CONVECTION LIKELY OVER
NORTHERN MONTANA. BIGGEST WEATHER IMPACT WILL BE POST FRONTAL
WINDS ESPECIALLY OVER THE EASTERN HALF OF THE AREA MONDAY NIGHT
WHERE THE GFS IS ADVERTISING NEARLY 2MB/HOUR PRESSURE RISES BEHIND
THE FRONT.

TUESDAY WILL BE WINDY BEHIND THE FRONT BUT A QUESTION ABOUT HOW
DRY BECAUSE THERE IS A HINT OF WRAP AROUND MOISTURE WORKING INTO
THE AREA. WOULD NOT EXPECT MUCH IN THE WAY OF PRECIPITATION BUT
CLOUD COVER COULD KEEP TEMPERATURES COOLER AND HUMIDITY HIGHER.
WILL CONTINUE TO ADVERTISE FIRE WEATHER CONCERNS FOR THE MONDAY
NIGHT THROUGH TUESDAY TIME FRAME DUE TO THE UNSEASONABLE STRENGTH
OF THIS SYSTEM.

THE REST OF THE EXTENDED IS DRY AND WARM WITH BREEZY AFTERNOONS
AS ZONAL FLOW ALOFT IS EXPECTED BUT A BIT STRONGER FLOW THAN
NORMAL. BORSUM


&&

.AVIATION...

ISOLATED THUNDERSTORMS EAST OF KBIL WILL DECREASE BY DAY BREAK.
ANOTHER ROUND OF THUNDERSTORMS EXPECTED EAST OF KBIL THIS
AFTERNOON. VFR CONDITIONS EXPECTED EXCEPT BRIEF REDUCTIONS TO MVFR IN
SHOWERS AND THUNDERSTORMS. BORSUM
&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SUN     MON     TUE     WED     THU     FRI
-------------------------------------------------------
BIL 092 062/090 062/080 054/075 055/086 058/092 061/091
    1/B 12/T    24/T    42/T    11/U    11/U    11/U
LVM 090 053/090 054/074 049/073 049/084 051/089 054/090
    2/T 12/T    35/T    53/T    11/B    11/U    11/B
HDN 093 059/093 058/086 053/077 053/087 056/093 059/093
    1/B 11/B    23/T    42/T    11/U    11/U    11/U
MLS 095 065/095 066/092 056/076 055/087 059/094 061/093
    2/T 11/U    22/T    43/T    11/U    11/U    11/U
4BQ 092 062/094 064/095 056/077 055/086 059/093 060/093
    2/T 11/U    22/T    32/T    11/U    11/U    11/U
BHK 092 061/093 063/092 056/075 054/084 056/090 058/089
    3/T 22/T    23/T    42/T    11/U    11/U    11/U
SHR 090 055/093 055/088 051/073 049/083 053/089 055/090
    2/T 11/U    22/T    22/T    11/U    11/U    11/U

&&

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

&&

$$
WEATHER.GOV/BILLINGS


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