104 
FXUS63 KBIS 220553
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1253 AM CDT MON JUL 22 2013

.UPDATE...
ISSUED AT 1253 AM CDT MON JUL 22 2013

NO SIGNIFICANT CHANGES REQUIRED WITH THIS FORECAST UPDATE OTHER
THAN TO BLEND TO THE OBSERVED TRENDS THROUGH 05 UTC. DID MAINTAIN
ISOLATED POPS THROUGH 08 UTC ACROSS THE JAMES RIVER VALLEY GIVEN
THE LATEST RADAR TRENDS. 

UPDATE ISSUED AT 953 PM CDT SUN JUL 21 2013

UPDATE TO REMOVE ALL COUNTIES FROM THE TORNADO WATCH AND COMPLETELY
CANCEL THE WATCH. UPDATES FORTHCOMING. EXPECT THE REST OF THE
NIGHT TO DRY OUT WITH TRANQUIL WEATHER COMMENCING.

UPDATE ISSUED AT 827 PM  CDT SUN JUL 21 2013

UPDATE TO REMOVE MOST OF OUR NORTH CENTRAL AND SOUTH CENTRAL
COUNTIES. PORTIONS OF OUR EAST CENTRAL ZONES REMAIN IN A TORNADO
WATCH UNTIL 10 PM CDT.

UPDATE ISSUED AT 714 PM CDT SUN JUL 21 2013

UPDATED THE FORECAST TO EXPAND THE TORNADO WATCH SOUTHEAST TO
INCLUDE THE JAMES RIVER BASIN. ALSO UPDATED THE FORECAST TO REMOVE
THE WATCH FROM THE WESTERN COUNTIES. ALSO ADJUSTED HOURLY POPS
BASED ON CURRENT RADAR OBS AND TRENDS. THE UPDATED GRIDDED AND
TEXT PRODUCTS HAVE BEEN SENT.

UPDATE ISSUED AT 431 PM CDT SUN JUL 21 2013

THIS UPDATE TO ADD SOUTH CENTRAL ND INCLUDING BURLEIGH...MORTON
AND KIDDER COUNTIES TO WATCH. 

UPDATE ISSUED AT 416 PM CDT SUN JUL 21 2013

THIS UPDATE TO CLEAR TORNADO WATCH FROM FAR NORTHWEST ND. 

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 245 PM CDT SUN JUL 21 2013

MAIN CONCERNS THIS SHORT TERM PERIOD WILL BE SEVERE STORMS. LATEST
SATELLITE LOOPS SHOW SHORTWAVE TROUGH MOVING THROUGH SASKATCHEWAN
INTO EASTERN MONTANA. A SURFACE TROUGH ASSOCIATED WITH THE
SHORTWAVE WAS ACTIVELY SUPPORTING A LINE OF THUNDERSTORMS. EXPECT
LINE OF THUNDERSTORMS DEVELOPING BETWEEN WILLISTON AND ESTEVAN
SASK...MOVING EAST WITH TIME ACROSS THE NORTH CENTRAL. LESS ACTIVE
THUNDERSTORM CHANCES SOUTH CENTRAL...BUT THREAT STILL EXISTS THIS
EVENING. LINE OF THUNDERSTORMS/MCS WILL EXIT THE REGION LATE
TONIGHT. HIGH PRESSURE WILL FOLLOW WITH COOLER AND DRY WEATHER
MONDAY. 

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 245 PM CDT SUN JUL 21 2013

THE MAIN CONCERN IN THE LONG TERM WILL BE THE CHANCES OF 
THUNDERSTORMS.  MUCH OF THE LONG TERM FORECAST PERIOD WILL FEATURE A 
H5 RIDGE ACROSS THE WESTERN UNITED STATES WITH A TROUGH IN THE 
EAST.  THIS WILL PLACE THE NORTHERN PLAINS IN NORTHWESTERLY 
FLOW ALOFT...WITH PERIODIC SHORTWAVES MOVING ACROSS NORTH DAKOTA.  

A SURFACE BOUNDARY IS EXPECTED TO BE LOCATED FROM NORTH CENTRAL 
MONTANA INTO EASTERN WYOMING MONDAY AFTERNOON.  THIS COULD PROVIDE 
THE FOCUS FOR THUNDERSTORMS MONDAY NIGHT...ESPECIALLY ACROSS WESTERN 
NORTH DAKOTA.  SURFACE HIGH PRESSURE BUILDS INTO NORTH DAKOTA ON 
TUESDAY...BUT QUICKLY SHIFTS EAST TUESDAY NIGHT.  THERE IS 
RELATIVE AGREEMENT AMONGST THE SHORT TERM MODELS THAT THUNDERSTORM 
CHANCES WILL RETURN TUESDAY NIGHT THOUGH THE PLACEMENT OF THE HIGHER 
CHANCES IS NOT AS CLEAR.  THE GFS AND ECMWF FAVOR THE NORTH AND EAST 
PARTS OF THE FORECAST AREA...AND THIS IS ALSO IN LINE WITH THE 
CURRENT FORECAST.  

A STRONGER WAVE MOVES ACROSS LATE IN THE WEEK...TOWARDS THURSDAY AND 
FRIDAY.  IT ALSO APPEARS A WARM FRONT SETS UP ACROSS SOUTHERN NORTH 
DAKOTA THURSDAY NIGHT INTO FRIDAY...WHICH SHOULD SHOULD BRING A MORE 
ORGANIZED CHANCE OF THUNDERSTORMS LATE IN THE WEEK.  

THE GFS AND ECMWF DIVERGE A BIT TOWARDS THE WEEKEND...THOUGH THE 
GENERAL IDEA IS THE H5 RIDGE BUILDS ACROSS NORTH DAKOTA WITH SURFACE 
HIGH PRESSURE TALKING HOLD ON SATURDAY.  THIS SHOULD HELP DRY IT OUT 
TO SOME EXTENT ON SATURDAY AND WILL STICK WITH SPOTTY SLIGHT CHANCE 
POPS.  ANOTHER BOUNDARY BECOMES ESTABLISHED ACROSS PARTS OF MONTANA 
INTO CENTRAL WYOMING FOR SUNDAY WITH THUNDERSTORM CHANCES 
POTENTIALLY INCREASING AGAIN IN THE WEST JUST BEYOND LONG TERM
FORECAST PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1253 AM CDT MON JUL 22 2013

MVFR STRATUS ACROSS SOUTHEAST SASKATCHEWAN IS EXPECTED TO CONTINUE
TO BUILD DOWN INTO NORTH DAKOTA...AND IMPACT KMOT AFTER 08 UTC.
SOME UNCERTAINTY REMAINS AS TO IF THIS STRATUS WILL BE ABLE TO
BUILD INTO KISN...AND THUS...LEFT IT OUT AT THIS TIME. DID ADD A
TEMPO GROUP FOR FOG AT KBIS TONIGHT GIVEN THE RAINFALL SUNDAY
EVENING...AND WILL HAVE TO MONITOR FOR POSSIBLE FOG/STRATUS
DEVELOPMENT AT KJMS GIVEN THE LATEST FOG CHANNEL SATELLITE TRENDS. 

&&

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

$$

UPDATE...AYD
SHORT TERM...WAA
LONG TERM...CK
AVIATION...AYD