Severe Thunderstorm Warning 123, NWS Bismarck, ND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
200 PM CDT THU JUL 17 2003

UPPR LVL HIGH PRESSURE REMAINS ENTRENCHED ACROSS THE FOUR CORNERS
AREA...WHILE FAST WESTERLY FLOW CONTINUES TO PROVIDE A CONVEYER BELT
OF WEAK S/W ENERGY TO THE REGION.  LATEST SFC OBS SHOW A MYRIAD OF
BNDRYS EXISTING ACROSS THE NORTHERN PLAINS...WITH SATELLITE PICS
INDICATING A SMATTERING OF OUTFLOW BNDRYS AS WELL.  THESE FACTORS
WILL CONTINUE TO MAKE CHANCES FOR TSTMS...THEIR COVERAGE AND
INTENSITY..THE MAIN FCST CONCERN.  WE WILL RELY MORE ON
MESOANALYSIS AND CONSISTENCY THAN NUMERICAL GUIDANCE SINCE NEITHER
THE ETA OR GFS HAVE TOTALLY CAUGHT THE SITUATION AT HAND...THOUGH
ADMITTEDLY THE GFS SEEMS TO HAVE A BETTER HANDLE THAN THE
ETA.

LOW LVL ESE FLOW HAS CONTINUED TO TRANSPORT INCREASING LOW LVL
MOISTURE INTO THE NORTHERN PLAINS...WITH TDS INTO THE 60S COMBINING
WITH SOLAR INSOLATION TO CAUSE SBCAPE VALUES OF 2500 TO 3500 J/KG IN
THE SW PART OF THE STATE.  MEANWHILE...ELEVATED CONVECTION WHICH HAS
PERSISTED TDY FURTHER NORTH AND EAST HAS LIKELY BEEN INGESTING SOME
OF THE ELEVATED INSTABILITY TO ITS W/SW.  WHILE THERE DOES NOT
APPEAR TO BE ANY SIG S/WS TO MOVE INTO THE AREA YET THIS
AFT...EXPECT CONTINUING HEATING AND SFC CONVERGENCE TO INITIATE
ADDITIONAL STORMS TO OUR WEST AS CIN CONTINUES TO ERODE...POSSIBLY
AS FAR EAST AS AS THE MT/ND BORDER.  GIVEN AFOREMENTIONED
INSTABILITY AND 0 TO 6 KM BULK SHEAR VALUES OF 30 TO 40 KTS...IF
STORMS ARE ABLE TO FORM THEY MAY ROTATE AND BECOME SVR.  EVEN IF
THIS DOES NOT OCCUR...CONVECTION WHICH FORMS ON THE HIGHER TERRAIN
WILL LIKELY MAKE ITS WAY INTO THE STATE LATER TONIGHT...THOUGH
LIKELY IN A WEAKER MANNER CONSIDERING LACK OF A STRONG LLJ.

THE BROKEN RECORD WILL LIKELY CONTINUE PLAYING FRIDAY...WITH
CONTINUED HIGH LOW LVL MOISTURE CONTENT AND PLENTIFUL STEEP MID LVL
LAPSE RATES AGAIN CONTRIBUTING TO STRONG...BUT INITIALLY
CAPPED...INSTABILITY.  MUCH LIKE THE PAST FEW DAYS...IF UPDRAFTS ARE
ABLE TO BREACH THE CAP...EXPLOSIVE TSTM DVLPMNT MAY OCCUR.
STILL...THERE DOES NOT APPEAR TO BE ANY MAJOR DYNAMICS
AVAILABLE...SO COVERAGE OF STORMS WILL BE SCATTERED AT MOST.  ON
SATURDAY...THE CHANCE OF STORMS WL CONTINUE AS THE SFC LOW MOVES
THROUGH...LIKELY MORE AT THE SPEED THE GFS SHOWS THAN THE ETA DOES.

LOOKING AHEAD...MEDIUM RANGE GUIDANCE IS IN EXCELLENT AGREEMENT ON
UPPR FLOW TURNING NW BY EARLY NEXT WEEK...THEN REBUILDING THE UPPR
RIDGE INTO THE AREA BY LATE WEEK.  THE END RESULT WILL BE A MAINLY
DRY FCST WITH TEMPS ONCE AGAIN WARMING TO SUMMERLIKE LVLS.

BIS...NONE.

SCHULTZ/TWH

NDZ001>005-009>013-017>023-025-031>037-040>048-050-051-180900-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BISMARCK ND
400 AM CDT THU JUL 17 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL NORTH
DAKOTA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT CHANCE OF STRONG TO SEVERE THUNDERSTORMS TONIGHT.
SOME STORMS MAY CONTAIN VERY HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THERE IS A SLIGHT CHANCE OF SEVERE THUNDERSTORMS ON FRIDAY NIGHT.
THE POSSIBILITY EXISTS FOR SOME OF THESE STORMS TO PRODUCE VERY
HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT AND FRIDAY NIGHT.

SHULZ

NDZ009-017-172125-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLISTON ND
227 PM CDT (127 PM MDT) THU JUL 17 2003

A LINE OF SHOWERS AND THUNDERSTORMS PERSISTS ALONG AND SOUTH OF THE
MISSOURI RIVER THIS AFTERNOON...AFFFECTING EXTREME SOUTHERN
WILLIAMS COUNTY AND THE NORTHERN HALF OF MCKENZIE COUNTY. AT 225 PM
CDT (125 PM MDT) THE STRONGEST STORM WAS LOCATED ON THE STATE LINE
NEAR FAIRVIEW. CLOUD TO GROUND LIGHTNING...PEA SIZE HAIL...WIND
GUSTS TO 45 MPH AND BRIEF PERIODS OF MODERATE RAIN ARE POSSIBLE
WITH THE STRONGER STORMS.

THOMSON

NDZ017-172215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLISTON ND
416 PM CDT (316 PM MDT) THU JUL 17 2003

...SEVERE THUNDERSTORM WATCH UNTIL 900 PM CDT (800 PM CDT)...

AT 415 PM CDT (315 PM MDT) SHOWERS AND THUNDERSTORMS CONTINUED
ACROSS MOST OF MCKENZIE COUNTY. LOCAL RADAR INDICATED THAT THE
STRONGEST STORM WAS IN RURAL SOUTHWEST MCKENZIE COUNTY...ABOUT 46
MILES SOUTH OF WILLISTON. AT THIS TIME NONE OF THESE STORMS ARE
SEVERE...BUT PERIODS OF HEAVY RAIN...CLOUD TO GROUND LIGHTNING...
WIND GUSTS TO 40 MPH AND PEA SIZE HAIL CAN BE EXPECTED.

THOMSON

ZCZC BISLSRBIS ALL

TTAA00 KBIS DDHHMM

PRELIMINARY LOCAL STORM REPORT

NATIONAL WEATHER SERVICE BISMARCK ND

520 PM CDT THU JUL 17 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...

           ....COUNTY LOCATION....

0505 PM    3 NW FAIRFIELD            ND   1 INCH HAIL

07/17/03   BILLINGS                       REPORTED BY STORM

                                          SPOTTER. MOSTLY PEA

                                          SIZED HAIL.

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ZCZC BISLSRBIS ALL

TTAA00 KBIS DDHHMM

PRELIMINARY LOCAL STORM REPORT

NATIONAL WEATHER SERVICE BISMARCK ND

621 PM CDT THU JUL 17 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...

           ....COUNTY LOCATION....

0615 PM    5 SW GOLVA                ND   1 INCH HAIL

07/17/03   GOLDEN VALLEY                  REPORTED BY LAW

                                          ENFORCEMENT OFFICIAL.

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