Severe Thunderstorm Warning 351, NWS Bismarck, ND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
200 PM CDT SUN SEP 23 2007

.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
MAIN FORECAST CONCERN IN THE SHORT TERM IS THE PRECIPITATION
ASSOCIATED WITH THE UPPER TROUGH AND FRONTAL SYSTEM MOVING THROUGH
THE NORTHERN PLAINS THIS EVENING. 12Z MODELS QUITE SIMILAR AND NOT
TOO DIFFERENT FROM YESTERDAY. HAVE GENERALLY FOLLOWED GFS.

CLOUDS AND A FEW LIGHT SHOWERS CONTINUE IN FAR WESTERN NORTH DAKOTA
THIS AFTERNOON TO THE WEST OF THE SURFACE TROUGH THAT LIES ACROSS
WESTERN NORTH DAKOTA. WITH UPPER FLOW CONTINUING FROM THE
SOUTH/SOUTHWEST...FRONTAL SYSTEM WILL BE SLOW MOVING. LOOKS LIKE IT
WILL BE 12Z OR AFTER BEFORE FRONT HAS PUSHED THROUGH ENTIRE CWA.

12Z BISMARCK SOUNDING WAS QUITE UNSTABLE ALOFT...BUT ALSO WAS
STRONGLY CAPPED. 12Z NAM12 SOUNDINGS FOR BISMARCK SHOWED DECREASING
CAP THIS AFTERNOON...BUT ALSO SHOWED DECREASING INSTABILITY. NAM AND
GFS BOTH INDICATE THAT BY THE TIME THE CAP WEAKENS...MAIN
INSTABILITY WILL BE EAST OF BISMARCK TOWARD JAMESTOWN. SO...EXPECT
MAIN SEVERE THREAT WITH HEAVIER RAIN WILL BE SOUTHEAST PART OF CWA.
SHOWER AND THUNDERSHOWER THREAT ALSO FOR WESTERN NORTH DAKOTA
TONIGHT...ESPECIALLY AFTER 06Z. THIS ASSOCIATED MORE WITH WRAPAROUND
TYPE PRECIP. SO...WILL HAVE FAIRLY HIGH POPS ENTIRE CWA.

STILL EXPECT SHOWERS TO TAPER OFF FROM THE NORTHWEST ON MONDAY
AFTERNOON AND EVENING. LEFT REMAINDER OF SHORT TERM FORECAST DRY FOR
NOW. GFS SHOWS A FAIRLY GOOD TROUGH MOVING THROUGH THE NORTHERN
PLAINS ON WEDNESDAY...BUT MODELS KEEPING THINGS DRY.

TEMPERATURES WILL BE COOL ON MONDAY WITH GUSTY NORTHWEST WINDS.
TEMPERATURES SHOULD REBOUND SOME FOR TUESDAY AND WEDNESDAY...BUT NO
BIG WARMUP WITH TEMPERATURES NOT TOO FAR FROM NORMAL.

.LONG TERM...THURSDAY THROUGH SUNDAY
ONLY ONE SYSTEM TO CONTEND WITH AT THIS TIME AND THAT WOULD BE
DURING THE FRIDAY NIGHT/SATURDAY TIME FRAME...WITH THE REMAINING
DAYS ON EITHER SIDE BEING DRY. THE GFS/ECMWF DIFFER ON THE STRENGTH
AND LOCATION OF THIS SYSTEM...BUT THE OVERALL TREND OF PAINTING SOME
SHOWERS ACROSS THE AREA SATURDAY IS STILL EVIDENT ON BOTH MODELS.
WILL SEE A WARMING TREND THURSDAY INTO FRIDAY...WITH FRIDAY BEING
THE WARMEST DAY AHEAD OF THE INCOMING COLD FRONT. EXPECT HIGHS TO
REACH WELL INTO THE 70S OVER THE AREA. THE FRONT LOOKS TO COME
THROUGH MAINLY DRY FRIDAY NIGHT...FOLLOWED BY THE UPPER LEVEL TROUGH
ON SATURDAY WHICH PRODUCES SOME SHOWERS. COOLER AIR ON SATURDAY WILL
GIVE WAY TO SOME WARMING AGAIN SUNDAY AS THE PROGRESSIVE
RIDGE/TROUGH PATTERN CONTINUES.
&&

.AVIATION...
A COLD FRONT OVER CENTRAL MONTANA AND A PRE-FRONTAL TROUGH OVER
CENTRAL NORTH DAKOTA WILL BOTH PRODUCE PRECIPITATION AND VARYING
CEILINGS OVER THE NEXT 12-24HRS. THE PRE-FRONTAL TROUGH WILL LIKELY
INITIATE SHOWERS AND THUNDERSTORMS OVER CENTRAL AND EASTERN NORTH
DAKOTA THIS AFTERNOON INTO THIS EVENING...SOME OF WHICH MAY BECOME
SEVERE. WOULD EXPECT MAINLY VFR CONDITIONS THE MAJORITY OF THE
TIME...THOUGH SOME BRIEF MVFR CONDITIONS ARE POSSIBLE BENEATH THE
HEAVIEST SHOWERS/THUNDERSTORMS. THE COLD FRONT OVER MONTANA WILL
MOVE INTO WESTERN NORTH DAKOTA AROUND MIDNIGHT...THEN INTO CENTRAL
NORTH DAKOTA MID-MORNING MONDAY BEFORE REACHING THE SOUTHEAST MONDAY
AFTERNOON. EXPECT SHOWERS TO ACCOMPANY THIS FRONT WITH WIDESPREAD
MVFR TO IFR CONDITIONS MONDAY MORNING INTO THE EARLY AFTERNOON.

&&

JF/KS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BISMARCK ND
459 AM CDT SUN SEP 23 2007

NDZ001-002-009-010-017-018-031>033-040-041-043-044-241000-
DIVIDE-BURKE-WILLIAMS-MOUNTRAIL-MCKENZIE-DUNN-GOLDEN VALLEY-
BILLINGS-STARK-SLOPE-HETTINGER-BOWMAN-ADAMS-
459 AM CDT SUN SEP 23 2007 /359 AM MDT SUN SEP 23 2007/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN NORTH
DAKOTA.

.DAY ONE...TODAY AND TONIGHT
THERE IS A CHANCE OF THUNDERSTORMS TODAY AND TONIGHT AS A LOW
PRESSURE SYSTEM MOVES FROM WESTERN NORTH DAKOTA TO MINNESOTA.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

NDZ003>005-011>013-019>023-025-034>037-042-045>048-050-051-241000-
RENVILLE-BOTTINEAU-ROLETTE-WARD-MCHENRY-PIERCE-MERCER-OLIVER-
MCLEAN-SHERIDAN-WELLS-FOSTER-MORTON-BURLEIGH-KIDDER-STUTSMAN-
GRANT-SIOUX-EMMONS-LOGAN-LA MOURE-MCINTOSH-DICKEY-
459 AM CDT SUN SEP 23 2007 /359 AM MDT SUN SEP 23 2007/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL NORTH
DAKOTA.

.DAY ONE...TODAY AND TONIGHT

A LOW PRESSURE SYSTEM IN WESTERN NORTH DAKOTA THIS MORNING WILL
MOVE SLOWLY ACROSS THE STATE TODAY AND TONIGHT. STRONG MOISTURE
ADVECTION EAST OF THE LOW WILL INCREASE AND DEEPEN THE POTENTIAL
INSTABILITY ACROSS CENTRAL NORTH DAKOTA TODAY BRINGING AN
INCREASING CHANCE OF THUNDERSTORMS THIS AFTERNOON AND TONIGHT. IF
THUNDERSTORMS DO DEVELOP...SOME COULD BE SEVERE WITH HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE MONDAY
MORNING AS THE SURFACE LOW MOVES INTO MINNESOTA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BISMARCK ND
745 PM CDT SUN SEP 23 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0741 PM     TSTM WND GST     VENTURIA                46.00N 99.55W
09/23/2007  E70 MPH          MCINTOSH           ND   TRAINED SPOTTER

            60 TO 70 MPH WINDS AND HEAVY RAIN

&&

KSIMOSKO