Area Forecast Discussion
Issued by NWS Bismarck, ND

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KBIS 270340
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1040 PM CDT SUN JUL 26 2015

.UPDATE...
ISSUED AT 1039 PM CDT SUN JUL 26 2015

SEVERE THUNDERSTORM WATCH HAS EXPIRED. ONLY A SMALL AREA OF
THUNDERSTORMS REMAINS...OVER GRANT AND SIOUX COUNTIES. KEPT HIGHER
CHANCES OF PRECIPITATION THERE THROUGH MIDNIGHT CDT...WITH SLIGHT
CHANCES TO THE NORTHEAST ALONG THE EARLIER CONVECTION AXIS.

ATTENTION THEN TURNS TO LATER TONIGHT WITH POTENTIAL CONVECTION OVER
NORTHWESTERN NORTH DAKOTA.

UPDATE ISSUED AT 840 PM CDT SUN JUL 26 2015

QUICK UPDATE TO TAKE SEVERAL COUNTIES OUT OF THE WATCH. ALL
NORTHERN TIER COUNTIES ARE NOW OUT...AND TOOK OUT SOME WESTERN
COUNTIES. THOSE REMAINING IN THE WATCH UNTIL 10 PM CDT INCLUDE
MCLEAN...MERCER...OLIVER...MORTON...HETTINGER...GRANT.

CONVECTION HAS WEAKENED SIGNIFICANTLY NORTH...AND EXPECT SOUTHERN
END OF LINE TO DIMINISH GRADUALLY THIS EVENING. HAD TO ADD SOME
MENTION OF CHANCE OF SHOWERS AND THUNDERSTORMS EASTWARD INTO
SHERIDAN/WELLS/BURLEIGH/KIDDER...AS STORMS HOLDING TOGETHER. DO
NOT EXPECT SEVERE STORMS OUTSIDE THE WATCH AREA...EXCEPT PERHAPS FOR
ADAMS/SIOUX COUNTIES.

UPDATE ISSUED AT 648 PM CDT SUN JUL 26 2015

A LINE OF STRONG TO SEVERE STORMS CONTINUES FROM BOTTINEAU/ROLETTE
COUNTY SOUTHWESTWARD TO BOWMAN COUNTY. SEVERE THUNDERSTORM WATCH
CONTINUES FOR THIS AREA AND EAST TO PIERCE/ROLETTE TO
MORTON/GRANT...BUT WILL ALLOW THE WATCH TO EXPIRE FOR SOME OF THE
WESTERN COUNTIES...NAMELY BURKE...MOUNTRAIL...MCKENZIE AND BILLINGS
COUNTIES.

LINE OF STORMS IS MAINLY ALONG A SURFACE FRONTAL BOUNDARY...WHICH
HAS MOVED EASTWARD DURING THE LATE AFTERNOON AND EVENING.

ADJUSTED HOURLY TEMPS/WINDS TO ACCOUNT FOR LATEST OBSERVATIONS AND
TRENDS.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 209 PM CDT SUN JUL 26 2015

BLENDED THE CURRENT POPS WITH THE HRRR ENSEMBLE FOR THE REMAINDER
OF THE AFTERNOON AND EVENING. AS OF 2 PM CDT THUNDERSTORMS HAVE
INITIATED ALONG THE FRONTAL BOUNDARY IN NORTHWEST NORTH DAKOTA.
BUFKIT 12Z SOUNDINGS SHOW A CAP IN PLACE SUNDAY AFTERNOON BIS-JMS
SO USED THIS AS THE EASTWARD EXTENT FOR THE CONVECTION THIS
AFTERNOON AND EVENING. 20Z WATER VAPOR IMAGE SHOWS WEAK TROUGH
MOVING THROUGH NORTHEAST MONTANA WITH THE MAIN UPPER LOW COMING ON
SHORE ACROSS WASH/OR. AS THE FLOW ALOFT BECOMES PARALLEL WITH THE
COLD FRONT IT WILL ONLY MAKE IT THROUGH WEST CENTRAL NORTH DAKOTA
SUNDAY EVENING...THEN LIKELY RETREAT TO THE NORTHWEST AS
INCREASING LOW LEVEL SOUTHEAST FLOW BECOMES MORE PREDOMINANT LATE
TONIGHT IN RESPONSE TO THE UPPER LOW MOVING TO MONTANA BY MONDAY
MORNING. AS THIS HAPPENS THE FOCUS FOR THUNDERSTORMS TONIGHT WILL
DIMINISH CENTRAL AND RETURN TO THE NORTHWEST.

ON MONDAY MID LEVEL COOLING AND INCREASING MID LEVEL ADIABATIC
LAPSE RATES WILL CREATE IMPRESSIVE CAPE VALUES IN EXCESS OF 4000.
WITH COLD FRONTAL BOUNDARY SET TO HELP BREAK THE CAP SEVERE
THUNDERSTORMS ARE ANTICIPATED ACROSS THE NORTHWEST MONDAY MORNING
AND ALONG AND WEST OF HIGHWAY 83 BY AFTERNOON.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 209 PM CDT SUN JUL 26 2015

THE MAIN FOCUS FOR THE LONG TERM IS THE POTENTIAL FOR A SEVERE
WEATHER OUTBREAK TOMORROW EVENING.

AN UPPER LEVEL TROUGH WILL DIG INTO THE NORTHERN ROCKIES TOMORROW.
THIS WILL PROVIDE AMPLE UPPER LEVEL ASCENT ACROSS THE NORTHERN
PLAINS AHEAD OF THE TROUGH. ADDITIONALLY...A DEEP SURFACE LOW AND
COLD FRONT WILL DEVELOP ACROSS EASTERN MONTANA...WITH A WARM
FRONT DRAPED ACROSS THE INTERNATIONAL BOARDER. AFTERNOON HEATING
ACROSS A VERY WARM AND MOIST WARM SECTOR WILL LIKELY YIELD CAPE
VALUES GREATER THAN 3000 J/KG. AFTERNOON CAPING DUE TO AN
ELEVATED WARM LAYER WILL LIKELY INHIBIT CONVECTION FROM FORMING
ACROSS ALL BUT FAR WESTERN NORTH DAKOTA UNTIL THE EARLY EVENING
HOURS...WHEN MID LEVEL COOLING AND STRONGER FORCING ARRIVES VIA
THE UPPER LEVEL WAVE. INITIALLY...ISOLATED SUPERCELLS ARE
POSSIBLE...WITH VERY LARGE HAIL...DAMAGING WINDS AND A FEW
TORNADOES. ONCE THE COLD FRONT AND UPPER LEVEL WAVE BEGINS PUSHING
EASTWARD ACROSS THE STATE...A TRANSITION TO DAMAGING LINE SEGMENTS
(WITH VERY STRONG WINDS AND SOME HAIL) APPEARS LIKELY.

DURING THE DAY TUESDAY...A SECONDARY PRESSURE SURGE WILL PRODUCE
VERY STRONG WINDS ACROSS THE REGION. WITH PRESSURE RISES BETWEEN
15 AND 20 MB/6HOUR...AND A STRONG DOWNSLOPE COMPONENT...WIND GUSTS
AROUND 50 MPH ARE POSSIBLE. TEMPERATURES TUESDAY WILL BE
CONSIDERABLY COOLER WITH READINGS ON AVERAGE 20 TO 30 DEGREES
COOLER THAN MONDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY NIGHT)
ISSUED AT 1039 PM CDT SUN JUL 26 2015

UPDATE:

CONVECTION IS NOT AN IMMEDIATE THREAT TO TAF SITES AT THIS TIME.
CHANCES INCREASE AT KISN MAINLY AFT 08Z.

VFR CONDITIONS EXPECTED ALTHOUGH LOW VFR CEILINGS POSSIBLE AT KISN
AFTER 12Z. MOST STRONG THUNDERSTORM ACTIVITY ON MONDAY SHOULD BE
AFTER 21Z AT KISN/KDIK AS THE COLD FRONT MOVES INTO THE STATE AND
THE STRONG UPPER LEVEL IMPULSES ARRIVE.

&&

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

$$

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.