Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 071454
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
954 AM CDT TUE JUL 7 2015

.UPDATE...
ISSUED AT 941 AM CDT TUE JUL 7 2015

06 UTC NAM AND LATEST ITERATIONS OF THE RAP/HRRR SEEM TO BE A
LITTLE TOO AGGRESSIVE IN DEVELOPING AND MOVING CONVECTION ACROSS
WESTERN NORTH DAKOTA THIS MORNING. LATEST RAP SHOWS 600-800 J/KG
OF CAPE AND 30KTS OF 0-6KM BULK SHEAR OVER WEST CENTRAL INTO
SOUTHWEST NORTH DAKOTA LATE THIS AFTERNOON SO THERE IS STILL
POTENTIAL FOR THUNDERSTORMS WITH A FEW STRONGER CELLS. FOR NOW
TRIMMED BACK ON THE EASTERN EXTEND OF CONVECTION THROUGH THIS
AFTERNOON.

ALSO EXTENDED THE MENTION OF SMOKE THROUGH THE AFTERNOON FOR ALL
BUT THE FAR EASTERN CWA. SMOKE HAD ABATED ACROSS MOST OF CENTRAL
AND EASTERN NORTH DAKOTA OVERNIGHT...BUT REMAINED OVER THE WEST. A
WEST TO NORTHWEST FLOW ALOFT WILL BRING THE SMOKE OVER THE
WEST...BACK INTO CENTRAL NORTH DAKOTA TODAY. SMOKE IS FROM THE
CANADIAN FIRES...IN ADDITION TO FIRES OVER THE NORTHWEST U.S.

UPDATE ISSUED AT 633 AM CDT TUE JUL 7 2015

ADJUSTED SMOKE DENSITY A BIT UP TO PATCHY SMOKE FROM AREAS OF
SMOKE AS OTHER THAN THE SOUTHWEST VISIBILITIES WERE GENERALLY 6
MILES OR BETTER. NAM CONTINUES TO SHOE 1500 OR BETTER CAPE ACROSS
THE SOUTHWEST BY NOON TODAY WHICH SHOULD SUPPORT AFTERNOON/EVENING
THUNDERSTORMS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT TUE JUL 7 2015

THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE CHANCES
FOR CONVECTION.

CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER THE
CENTRAL/EASTERN DAKOTAS. SKIES WERE CLEAR OVER THE STATE.
VISIBILITIES WERE REDUCED TO AROUND 4 MILES DUE TO SMOKE AT
DICKINSON AND HETTINGER IN SOUTHWESTERN NORTH DAKOTA...AND ALSO AT
SIDNEY MONTANA. WILL STILL KEEP A MENTION OF SMOKE THROUGH THE
MORNING OVER MAINLY WESTERN NORTH DAKOTA...AND WITH SOUTH WINDS
INCREASING A BIT THIS AFTERNOON WILL TAKE THE MENTION OF SMOKE OUT
FOR THE AFTERNOON.

AT UPPER LEVELS...NORTHWEST FLOW CONTINUES WITH THE TAIL END OF A
JET STREAK ORIENTED NORTHWEST TO SOUTHEAST ACROSS NORTH DAKOTA EARLY
THIS MORNING.

TODAY AN UPPER LEVEL SHORTWAVE TROUGH IS FORECAST TO APPROACH
WESTERN NORTH DAKOTA LATER THIS MORNING AND MOVE EAST ACROSS THE
REGION TONIGHT AND WEDNESDAY. THE LEADING EDGE OF UPPER LEVEL
IMPULSES ASSOCIATED WITH THE TROUGH REACHES WESTERN NORTH DAKOTA
LATE THIS MORNING. BY THIS AFTERNOON...SOUTHWESTERN NORTH DAKOTA IS
IN THE RIGHT REAR QUADRANT OF THE AFOREMENTIONED JET STREAK. ANOTHER
JET STREAK MOVING OUT OF WYOMING MOVES ACROSS SOUTH DAKOTA AND INTO
CENTRAL/SOUTHERN MINNESOTA THIS AFTERNOON AND TONIGHT. THIS
SCENARIO WILL ENHANCE INSTABILITY ACROSS THE REGION AND INDUCE
SURFACE LOW PRESSURE FROM SOUTHERN SASKATCHEWAN TO WYOMING THIS
AFTERNOON. THIS SURFACE LOW PRESSURE TROUGH IS FORECAST TO
MOVE/DEVELOP EASTWARD INTO THE WESTERN DAKOTAS TONIGHT.

INTRODUCED SOME SLIGHT CHANCE MENTION OF THUNDERSTORMS IN THE FAR
SOUTHWEST LATE THIS MORNING. ISOLATED TO SCATTERED THUNDERSTORMS
EXPECTED THIS AFTERNOON OVER THE WESTERN HALF OF THE STATE...AND
ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT. BEST CAPE
REMAINS IN THE WESTERN PART OF THE STATE MORE ALIGNED WITH THE
SURFACE TROUGH. BEST SHEAR IS ACROSS SOUTHERN NORTH DAKOTA AND INTO
SOUTH DAKOTA. THE BEST CHANCE OF STRONG STORMS WOULD BE ACROSS
SOUTHWESTERN NORTH DAKOTA...MAINLY LATE AFTERNOON AND EARLY EVENING
WHEN BULK SHEAR IS FORECAST TO BE STRONGEST AT AROUND 40-45 KNOTS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 300 AM CDT TUE JUL 7 2015

THE PROMINENT UPPER LOW ACROSS CANADA BEGINS TO FILL AND MIGRATE
NORTH AS A PACIFIC FLOW BEGINS TO EMERGE ACROSS WESTERN NORTH
AMERICA IN THE EXTENDED PERIOD. THIS WILL EVENTUALLY BRING
SOUTHWEST FLOW ALOFT WITH IMPULSES MOVING INTO THE NORTHERN
PLAINS BY THE END OF THE WORK WEEK INTO THE WEEKEND. THIS WILL BE
FOLLOWED BY A RETROGRADING H500 RIDGE OVER THE SOUTHERN PLAINS
NORTH INTO THE NORTHERN PLAINS BY MONDAY WHICH SHOULD BRING IN A
MORE TYPICAL JULY WARMTH. WEDNESDAY WILL SEE HIGHS IN THE
70S...GRADUALLY WARMING THROUGH THE 80S INTO THE WEEKEND AND
POSSIBLY 90 BY MONDAY. THE BEST CHANCES FOR THUNDERSTORMS WILL BE
SATURDAY AND SUNDAY WHEN THE PACIFIC/TROPICAL FLOW REACHES THE
NORTHERN PLAINS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 941 AM CDT TUE JUL 7 2015

HIGH PRESSURE WAS CENTERED OVER EASTERN NORTH DAKOTA. CLEAR SKIES
ACROSS TAF SITES. KDIK AND KHEI WERE REPORTING 3-5SM IN SMOKE THE
PAST FEW HOURS. PUT IN SCATTERED DECK AS WHEN SMOKE BECOMES THICKER
THE ASOS REPORTS THE SMOKE AS A CLOUD LAYER. EXPECT IMPROVING
CONDITIONS TO VFR VSBYS EXPECTED AS SOUTHERLY WINDS INCREASE TODAY.

CHANCE OF THUNDERSTORMS BEGINS THIS AFTERNOON IN THE
SOUTHWEST...SPREADING NORTH AND EAST ACROSS THE STATE TUESDAY NIGHT.
MENTIONED VCTS AT TAF SITES. LATER TAF ISSUANCES MAY ADD TEMPO GROUP
WITH -TSRA AS TIME OF OCCURRENCE APPROACHES. CHANCE OF THUNDERSTORMS
TO CONTINUE THROUGH TONIGHT. VFR CONDITIONS EXPECTED EXCEPT IN THE
VICINITY OF THUNDERSTORMS.

&&

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

$$

UPDATE...TWH
SHORT TERM...JV
LONG TERM...WAA
AVIATION...TWH


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