Severe Thunderstorm Warning 213, NWS Bismarck, ND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
400 AM CDT WED JUL 16 2008

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT...
USE A BLEND OF THE NAM AND GFS FOR THIS FORECAST PACKAGE. UPPER
LEVEL FLOW IS FAIRLY ZONAL FROM WEST TO EAST THROUGHOUT THE SHORT
TERM WITH MANY SHORTWAVES MOVING ACROSS THE STATE. THIS MORNING
CONVECTION FLARED UP AS ELEVATED THUNDERSTORMS WITH FORECAST VORT
ENERGY STRENGTHENING...AND CONTINUING EASTWARD TODAY. ALREADY ISSUED
ONE WARNING AND STORM PREDICTION CENTER THINKING SEVERE POTENTIAL IS
HERE ALREADY THIS MORNING. PLENTY OF CAPE AND LOW LEVEL MOISTURE TO
CONTINUE INTO THE AFTERNOON AS BROAD SURFACE LOW PRESSURE OVER
WYOMING AND SOUTH DAKOTA KEEPS EAST TO NORTHEAST WINDS AND
INCREASING DEWPOINTS THROUGHOUT THE DAY TODAY. WILL MENTION POSSIBLY
SEVERE WORDING FOR ALL BUT THE FAR WEST TODAY.

ON THURSDAY THERE WILL BE LESS OF A CHANCE OF THUNDERSTORMS WITH
SURFACE HIGH MOVING EAST ACROSS THE STATE...BUT STILL PLENTY OF
UPPER LEVEL SHORTWAVES MOVING ACROSS NORTH DAKOTA AND THERE IS CAPE.
THURSDAY NIGHT KEPT MENTION OF PRECIP ONLY IN THE FAR SOUTH.

ON FRIDAY A BETTER CHANCE OF THUNDERSTORMS AGAIN WITH POSSIBLE
SEVERE STORMS AS UPPER LOW/TROUGH OVER THE ROCKIES MOVES INTO THE
STATE WITH A DEVELOPED SURFACE LOW OVER THE DAKOTAS FRIDAY NIGHT.

.LONG TERM...SATURDAY THROUGH TUESDAY...
FORECAST PROBLEM IN THE LONG TERM WILL BE THUNDERSTORM CHANCES.
ECMWF AND GFS STILL DIFFER IN THE HANDLING OF A WAVE MOVING ACROSS
SOUTHERN CANADA AND INTO THE LOCAL AREA AT THE BEGINNING OF THE LONG
TERM PERIOD. ECMWF REMAINS FARTHER NORTH WITH THE WAVE COMPARED TO
THE GFS. OVERALL THOUGH THE MODELS HAVE COME INTO CLOSER AGREEMENT
WITH THIS SYSTEM. HAVE THEREFORE ADJUSTED POPS A BIT FOR TIMING OF
THE WAVE. MOST SIGNIFICANT CHANGE FROM PREVIOUS FORECAST WAS ENDING
THE THUNDERSTORM CHANCES A BIT EARLIER FROM WEST TO EAST SUNDAY AND
SUNDAY NIGHT. BOTH MODELS BRING AN AREA OF CONVECTION ACROSS THE
REGION SATURDAY INTO SATURDAY NIGHT. THEN UPPER LEVEL RIDGING BUILDS
OVER THE WEST ON SUNDAY. IT APPEARS THAT ANY CONVECTION ON SUNDAY
WILL REMAIN OVER THE EASTERN HALF OF THE CWA. VERY FEW CHANGES TO
TEMPERATURES IN THE DAY 4-5 PERIOD. MODELS DIVERGE IN THEIR
SOLUTIONS BEYOND THIS WITH THE GFS BUILDING AN UPPER RIDGE OVER THE
WESTERN AND CENTRAL U.S. WHILE THE ECMWF BRINGS ANOTHER WAVE OFF
THE PACIFIC COAST AND INTO THE NORTHERN PLAINS LATE IN THE EXTENDED
PERIOD.
&&

.AVIATION...
CONVECTION FIRING EARLY THIS MORNING OVER WESTERN AND CENTRAL NORTH
DAKOTA...NORTH OF AN EAST-WEST BOUNDARY ACROSS SOUTH DAKOTA.
SHORTWAVE MOVING ACROSS SOUTHERN SASKATCHEWAN IS HELPING TO FIRE
CONVECTION IN AN AREA OF STEEP MID LEVEL LAPSE RATES OVER SOUTHERN
NORTH DAKOTA. CONVECTION WILL TO PROGRESS EAST THIS MORNING...AND
EXIT THE JMS AREA BY MIDDAY. ADDITIONAL CONVECTION IS POSSIBLE AGAIN
THIS AFTERNOON ACROSS WESTERN AND CENTRAL NORTH DAKOTA WITH
AFTERNOON HEATING ALONG AND AHEAD OF A WEAK SURFACE AND UPPER LEVEL
TROUGH. SURFACE FLOW WILL BE LIGHT AND VARIABLE OVER THE AREA TODAY.
EXPECT MAINLY VFR CONDITIONS...EXCEPT AREAS OF MVFR VSBYS IN AREAS
OF CONVECTION.
&&

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

JV/TWH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BISMARCK ND
236 AM CDT WED JUL 16 2008

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

0228 AM     HAIL             HALLIDAY                47.35N 102.34W
07/16/2008  E1.00 INCH       DUNN               ND   CO-OP OBSERVER

            PENNEY...NICKEL...AND QUARTER SIZE HAIL LASTED UNTIL 235
            AM CDT.

&&

SWICHE