Area Forecast Discussion
Issued by NWS Bismarck, ND

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000
FXUS63 KBIS 060235
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
935 PM CDT SUN JUL 5 2015

.UPDATE...
ISSUED AT 934 PM CDT SUN JUL 5 2015

BASED ON RADAR TRENDS AND HI-RESOLUTION MODEL OUTPUT...OPTED TO
DECREASE POPS NORTH AND WEST OF THE CURRENT AREA OF RAIN. DID NOT
GET RID OF THEM COMPLETELY...BUT DID CREATE A MUCH TIGHTER POP
GRADIENT. WE ALSO LIMITED THE ISOLATED THUNDER CHANCES EVEN
MORE...WITH AN ISOLATED MENTION IN THE SOUTHERN JAMES RIVER
VALLEY. HELD ONTO THE NEXT CHANCE OF SHOWERS OVERNIGHT AS ANOTHER
WAVE MOVES INTO NORTH DAKOTA FROM MONTANA. THE LATEST ITERATION OF
THE RAP13 SHOWS THE WAVE WEAKENING AS IT APPROACHES...SO KEPT
POPS RELATIVELY LOW FOR NOW.

UPDATE ISSUED AT 829 PM CDT SUN JUL 5 2015

QUICK UPDATE WAS SENT TO INCREASE POPS IN THE SOUTHEAST CORNER OF
THE FORECAST AREA AND DECREASE ANY THUNDERSTORM MENTION TO
ISOLATED. THE LATEST HRRR SUGGESTS THE RAIN IN THE SOUTHERN JAMES
RIVER VALLEY SHOULD LAST ANOTHER FEW HOURS BEFORE DIMINISHING.
MUCAPE HAS DIMINISHED SUBSTANTIALLY OVER THE PAST COUPLE OF HOURS
WITH ANY LINGERING INSTABILITY SHOWN MAINLY TOWARDS THE SOUTHERN
JAMES RIVER VALLEY.

UPDATE ISSUED AT 651 PM CDT SUN JUL 5 2015

GENERALLY FOLLOWED THE TRENDS IN THE LATEST HI-RES MODELS FOR
PRECIPITATION PLACEMENT TONIGHT. SHOWERS / ISOLATED THUNDERSTORMS
IN THE CENTRAL PART OF THE FORECAST AREA HAVE DIMINISHED...WHILE
ADDITIONAL SHOWERS HAVE BEEN RISING NORTH OUT OF SOUTH DAKOTA.
THIS WILL KEEP THE BEST CHANCES OF RAIN IN THE SOUTHERN PART OF
THE STATE THIS EVENING. A H5 WAVE MOVING EAST ACROSS MONTANA WILL
BRING ANOTHER CHANCE OF SHOWERS LATER TONIGHT. OVERALL THE
FORECAST HAS CAUGHT THE TRENDS WELL...SO MAIN ADJUSTMENTS WERE TO
REFINE POPS.

SMOKE FROM THE CANADIAN WILD FIRES HAS AGAIN REDUCED VISIBILITIES
ACROSS PARTS OF WESTERN AND CENTRAL NORTH DAKOTA. IT IS HARD TO
KNOW FOR SURE HOW LOW VISIBILITIES MAY DROP...BUT WILL CONTINUE TO
CARRY AREAS OF SMOKE IN THE GRIDS AND MONITOR FOR THE POSSIBILITY
OF ISSUING ANOTHER SPECIAL WEATHER STATEMENT.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 221 PM CDT SUN JUL 5 2015

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

CURRENT RADAR AND SATELLITE ANALYSIS INDICATE A DYING LINE OF
CONVECTION PUSHING OUT OF THE FAR SOUTHEAST PORTION OF THE CWA
ALONG THE SURFACE COLD FRONT. ANOTHER AREA OF SHOWERS AND ISOLATED
THUNDER IS EXTENDING FROM SOUTHEAST MONTANA INTO SOUTHWEST NORTH
DAKOTA. WITH THE COLD FRONT NOW THROUGH THE FORECAST AREA THINK
THE THREAT OF SEVERE WEATHER WILL BE MINIMAL...THUS HAVE REMOVED
SEVERE WORDING FOR LATE AFTERNOON AND TONIGHT. THE CONVECTION
STREAMING IN FROM MONTANA IS ASSOCIATED WITH THE MID-UPPER LEVEL
TROUGH AND ASSOCIATED 100KT JET SWINGING ACROSS THE SOUTHERN
CANADIAN PRAIRIE PROVINCES AND NORTH CENTRAL U.S. THIS CONVECTION
IS WELL BEHIND THE COLD FRONT AND IS NOT EXPECTED TO BE SEVERE.
WITH THE UPPER LEVEL JET REMAINING OVER THE AREA THROUGH THE
NIGHT WE EXPECT THE THREAT OF SHOWERS AND ISOLATED THUNDER WILL
REMAIN THIS EVENING...WITH SHOWERS AFTER MIDNIGHT. THE HIGHEST
CHANCES WILL LINE UP WITH THE UPPER JET IN A NORTHEAST TO
SOUTHWEST BAND.

ON MONDAY...THE UPPER LEVEL TROUGH TRACKS ACROSS THE NORTHERN
FORECAST ZONES. WHILE SURFACE HIGH PRESSURE BUILDS FROM THE WEST.
SHOULD BE ENOUGH INSTABILITY WITH THE COLDER TEMPERATURES ALOFT TO
CREATE SOME SHOWERS ACROSS THE NORTHERN AND EASTERN CWA. WITH
DRIER AIR COMING IN FROM THE WEST...THE LAYER OF MOISTURE IS
RATHER THIN...AROUND 5-7K FEET...WITH VERY DRY AIR ABOVE. THUS
WILL KEEP THE SHOWER WORDING AND NOT INTRODUCE ANY THUNDER. IT
WILL BE COOLER ON MONDAY WITH HIGHS IN THE MID 60S TO LOWER 70S.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 221 PM CDT SUN JUL 5 2015

TRANQUIL WEATHER MONDAY NIGHT INTO MOST OF TUESDAY WITH SURFACE HIGH
PRESSURE IN PLACE ALONG WITH A QUASI WEST TO NORTHWEST FLOW ALOFT.
SMOKE/HAZE ISSUES CARRIED OVER FROM THE SHORT TERM SHOULD AGAIN
CONTINUE IN THE EARLY PART OF THE EXTENDED FORECAST. CHANCES OF
SHOWERS AND THUNDERSTORMS THEN INCREASE TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT FOLLOWED BY DRIER WEATHER THURSDAY AND FRIDAY. A
MORE ACTIVE PERIOD RESUMES FOR THE UPCOMING WEEKEND. A WARMING TREND
THROUGH THE WEEK IS EXPECTED WITH AFTERNOON HIGHS IN THE LOWER TO
MID 70S TUESDAY...GRADUALLY RISING TO THE MID AND UPPER 80S OVER THE
WEEKEND.

MONDAY NIGHT INTO TUESDAY MORNING...A 1021MB SURFACE HIGH PRESSURE
WITH A QUASI WEST TO NORTHWEST FLOW ALOFT AND A LACK OF ANY
SIGNIFICANT SHORTWAVES WILL PRODUCE A TRANQUIL WEATHER MONDAY NIGHT
INTO TUESDAY MORNING. DRIER MORE COMFORTABLE AIR WILL ENSUE WITH
DEWPOINTS/LOW TEMPERATURES RANGING BETWEEN 45F AND 50F TUESDAY
MORNING. HOWEVER AS MENTIONED ABOVE...SMOKE/HAZE WILL LIKELY
CONTINUE THROUGH TUESDAY.

TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...SURFACE HIGH PRESSURE
DEPARTS AS IT MOVES INTO MINNESOTA ALLOWING FOR A RETURN OF LOW
LEVEL SOUTHERLY FLOW INTO WESTERN NORTH DAKOTA AROUND THE HIGH.
DEWPOINTS WILL BEGIN RISING INTO THE 50S DURING THE DAY. A COLD
FRONT WILL SLIDE ACROSS SOUTHWESTERN/SOUTH CENTRAL SASKATCHEWAN
DURING THE DAY...THEN INTO NORTHERN NORTH DAKOTA AND MANITOBA
TUESDAY NIGHT. THIS FRONT STALLS OVER SOUTHWEST AND INTO SOUTH
CENTRAL NORTH DAKOTA TUESDAY NIGHT AND WEDNESDAY. A LEESIDE SURFACE
LOW/TROUGH ALSO INITIATES OVER SOUTHEAST MONTANA INTO EASTERN
WYOMING TUESDAY. DATA INDICATING MOISTURE CONVERGENCE IN THE
VICINITY OF THE LEE SIDE LOW ACROSS SOUTHWEST NORTH DAKOTA TUESDAY
AFTERNOON...WITH RESULTANT ISOLATED SHOWERS/THUNDERSTORMS DEVELOPING
DURING THE AFTERNOON. BOTH THE GFS AND ECMWF SHOWS SIMILAR 0-6KM
SHEAR VALUES AT 33KTS...WITH CAPE AROUND 600 J/KG PER GFS AND LESS
THAN 100 J/KG IN THE ECMWF. SOMEWHAT BETTER FORCING ARRIVES TUESDAY
NIGHT WITH THE TAIL END OF A JET STREAK IN SOUTHERN CANADA/NORTHERN
NORTH DAKOTA...AND ANOTHER JET STREAK IN SOUTHERN NORTH DAKOTA. WILL
KEEP A CHANCE OF SHOWERS/THUNDERSTORMS MAINLY SOUTHERN NORTH DAKOTA
TUESDAY NIGHT. WEDNESDAY LOOKS TO BE A BETTER DAY FOR CHANCES OF
SHOWERS/THUNDERSTORMS WITH A SHORTWAVE AND ASSOCIATED JET STREAK
SLIDING ATOP OF THE NEARLY STALLED FRONT IN SOUTHWEST/SOUTH CENTRAL
NORTH DAKOTA.

THURSDAY THROUGH FRIDAY...PRECIPITATION CHANCES WANE WEDNESDAY NIGHT
WITH THE UPPER LEVEL FLOW TRANSITIONING TO SOUTHWESTERLY FLOW. MID
LEVEL RIDGING/H7-H5...WILL RESULT IN A MAINLY DRY FORECAST. THERE
APPEARS TO BE A COUPLE OF SHORTWAVES MOVING INTO THE MID LEVEL
RIDGE...BUT NOT ENOUGH VERTICAL MOTION TO PRODUCE ANY SIGNIFICANT
PRECIPITATION. THE OVERALL TREND BETWEEN THE GFS/ECMWF AND
SUPERBLEND IS FOR A DRY FORECAST.

FRIDAY NIGHT THROUGH SUNDAY...MID LEVEL RIDGING SHIFTS EAST WITH A
SERIES OF MID LEVEL SHORTWAVE TROUGHS AND ASSOCIATED SURFACE
FEATURES TO IMPINGE ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THIS
SUPPORTS INCREASING CHANCES FOR SHOWERS/THUNDERSTORMS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 651 PM CDT SUN JUL 5 2015

REDUCED VISIBILITIES IN SMOKE WILL BE THE BIGGEST CONCERN FOR THE
00Z TAF PERIOD. SEVERAL LOCATIONS ACROSS WESTERN AND CENTRAL NORTH
DAKOTA REPORT MVFR VISIBILITIES...WITH SOME REPORTS OF IFR. WILL
CARRY AT LEAST MVFR VISIBILITIES AT MOST TERMINAL LOCATIONS...WITH
IFR ALSO POSSIBLE IN THE NORTH AND WEST (KISN...KMOT...KDIK). AN
ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE AT KDIK...KBIS AND
KJMS...BUT ONLY CARRIED A BRIEF PERIOD OF RAIN AT KJMS BASED ON
NEAR TERM RADAR TRENDS.


&&

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

$$

UPDATE...CK
SHORT TERM...TWH
LONG TERM...KS
AVIATION...CK


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