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000
FXUS63 KBIS 010834
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
334 AM CDT FRI AUG 1 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT FRI AUG 1 2014

CURRENTLY...A SURFACE LOW WAS OVER EASTERN MONTANA WHILE BROAD HIGH
PRESSURE STRETCHES FROM MANITOBA THROUGH THE EASTERN DAKOTAS INTO
THE MINNESOTA. AT UPPER LEVELS A RIDGE EXTENDED FROM THE GREAT BASIN
INTO THE NORTHERN ROCKIES WHILE AN UPPER LEVEL LOW SPINS NEAR JAMES
BAY BRINGING NORTH-NORTHWESTERLY FLOW TO OUR AREA WITH A VARIETY OF
WEAK IMPULSES SLIDING THROUGH.

A SMALL CLUSTER OF THUNDERSTORMS OVER SOUTH CENTRAL SASKATCHEWAN...IN
THE SWIFT CURRENT AREA...CONTINUED TO SUSTAIN ITS CONVECTION THROUGH
THE EARLY MORNING HOURS. THE MODELS DEPICT A WEAK UPPER LEVEL
IMPULSE IN THE AREA WHERE CURRENT THUNDERSTORM ACTIVITY WAS
OCCURRING. THE NAM DEPICTS THE WEAK UPPER LEVEL IMPULSE MOVING
SOUTHEASTWARD SLOWLY...APPROACHING NORTHWESTERN NORTH DAKOTA
BEFORE/AROUND DAYBREAK...THEN MOVING THROUGH SOUTHWESTERN NORTH
DAKOTA FRIDAY AFTERNOON.

LATER TODAY...THE MODELS INDICATE THE EASTERN MONTANA SURFACE LOW
DEVELOPS SOUTHWARD AND AN EAST-WEST SURFACE FRONTAL BOUNDARY BECOMES
ESTABLISHED OVER NORTHERN SOUTH DAKOTA. THIS SURFACE BOUNDARY
COMBINED WITH WEAK UPPER LEVEL IMPULSES MOVING THROUGH THE
NORTHWESTERLY FLOW ALOFT SHOULD RESULT IN BETTER CHANCES OF
CONVECTION IN SOUTH DAKOTA...THUS WILL KEEP THE MENTION OF SLIGHT
CHANCE OF THUNDERSTORMS ACROSS THE SOUTH.

FRIDAY NIGHT...THE UPPER LEVEL IMPULSE AND ASSOCIATED SURFACE
BOUNDARY IN SOUTH DAKOTA MOVES FARTHER SOUTH. ATTENTION THEN TURNS
TO THE NEXT UPPER LEVEL IMPULSE MOVING SOUTHEASTWARD OUT OF
SASKATCHEWAN. THIS FEATURE APPROACHES NORTHWESTERN NORTH DAKOTA
FRIDAY EVENING...AND IS PROGGED TO REACH THE CENTRAL DAKOTAS AFTER
MIDNIGHT. WILL KEEP SLIGHT CHANCES OF THUNDERSTORMS NORTHWEST THIS
EVENING...WITH ISOLATED TO SCATTERED CHANCES LATE.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 333 AM CDT FRI AUG 1 2014

A MORE ACTIVE WEATHER PATTERN WILL HIGHLIGHT THE EXTENDED FORECAST.

THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN GOOD AGREEMENT
ON AN UPPER LEVEL RIDGE CENTERED ACROSS THE INTERMOUNTAIN WEST
THIS WEEKEND...SLOWLY BREAKING DOWN WITH A TRANSITION TO NEAR
ZONAL FLOW EARLY NEXT WEEK. THIS SUPPORTS DAILY CHANCES FOR
THUNDERSTORMS ASSOCIATED WITH IMPULSES PROPAGATING ALONG THE
NORTHERN PERIPHERY OF THE RIDGE AND EMBEDDED WITHIN THE ZONAL
FLOW. CERTAINLY CANNOT RULE OUT AN ISOLATED SEVERE THREAT EACH DAY
SUNDAY THROUGH WEDNESDAY...HOWEVER...A WIDESPREAD SEVERE THREAT
IS NOT EXPECTED AT THIS TIME.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1239 AM CDT FRI AUG 1 2014

VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. CONVECTION
POSSIBILITIES ARE LOW ENOUGH THAT WE WILL NOT CARRY ANY VCTS WITH
THE 06 UTC TAF ISSUANCE. WATCHING A SMALL CLUSTER OF THUNDERSTORMS
OVER SOUTH CENTRAL SASKATCHEWAN...AND WILL MONITOR IN CASE
THUNDERSTORMS APPROACH KISN AFT 09Z. LIGHT AND VARIABLE SURFACE FLOW
TONIGHT BECOMING MORE EASTERLY ON FRIDAY...YET REMAINING UNDER 15
KNOTS.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...JV
LONG TERM...AYD
AVIATION...JV