Severe Thunderstorm Warning 108, NWS Grand Forks, ND

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GRAND FORKS ND
1058 AM CDT SAT JUL 17 2010

.DISCUSSION...MAIN CONCERN TODAY IS SEVERE THUNDER POTENTIAL.
STILL LOTS OF QUESTIONS REGARDING DETAILS (SUCH AS POSITION OF WARM
FRONT...INITIATION...CLOUD COVER...AREAL EXTENT OF THUNDER
COVERAGE). NAM/GFS HAVE WARM FRONTAL POSITION SOUTH OF THE FA BY
21Z/00Z...WHILE GEM/RUC/ECMWF/SREF POSITION IT ACROSS THE SOUTHERN
FA. CONSIDERING CURRENT LOCATION (JUST NORTH OF A JMS-FAR-PKD
LINE)...DO NOT THINK THAT IT RETREAT TOO FAR SOUTH BY THIS
AFTERNOON. PREVIOUS THINKING REGARDING SEVERE POTENTIAL REMAINS
ABOUT THE SAME. CURRENT ISOLD ELEVATED CONVECTION ASSOCIATED WITH
STRONGER WARM AIR ADVECTION MAY CONTINUE INTO THE EARLY AFTERNOON
HOURS BEFORE DISSIPATING. THEN...EXPECT MID-AFTERNOON INITIATION OF
SEVERE STORMS. 850MB-750MB TEMPS QUITE WARM ALONG AND SOUTH OF WARM
FRONT...AND MAY ACT TO CAP ATMOSPHERE FOR A TIME. THERE SHOULD BE
STRONG ENOUGH FORCING (COLD FRONT...UPPER JET) BY MID-LATE
AFTERNOON TO INITIATE STORMS WHERE STRONGEST INSTABILITY SETS UP
(MOST LIKELY ACROSS THE SOUTHERN 2/3RDS OF THE FA...DEPENDING ON
WARM FRONTAL POSITION). VERY STRONG DEEP LAYER SHEAR (50KNTS-
70KNTS) AND INSTABILITY (MLCAPE 2500-3500 J/KG) LEADS TO THE SPC
MODERATE RISK. MADE SOME MINOR ADJUSTMENTS TO THE POP/WX GRIDS FOR
TIMING PURPOSES (EXITING SYSTEM A BIT QUICKER)...BUT OTHERWISE
FORECAST IN GOOD SHAPE.

&&

.AVIATION...VFR CONDITIONS EXPECTED THIS AFTERNOON AND TONIGHT
HOWEVER MVFR TO IFR CONDITIONS POSSIBLE IN THUNDERSTORMS.

&&

.PREV DISCUSSION... /ISSUED 430 AM CDT SAT JUL 17 2010/

SHORT TERM...TODAY THROUGH MONDAY NIGHT.
GFS CONTINUES TO RUN FASTER THAN THE ECMWF, GEM AND NAM. THE ECMWF
WAS THE SLOWEST AND THE NAM AND GEM A COMPROMISE. UPPER LEVEL RIDGE
REMAINS OVER THE DESERT SOUTHWEST THEN SHIFTS INTO THE SOUTHERN
PLAINS LATE THIS PERIOD. MID LEVEL CAP ALSO ROLLS OUT INTO THE ND
AND CENTRAL PLAINS THIS MORNING AND STATES TO THE SOUTH THIS
AFTERNOON.

PRECIPITABLE WATER RISES TO NEAR TWO INCHES THIS AFTERNOON IN THE
SOUTHERN COUNTIES. CROSS SECTION INDICATES IMPRESSIVE DRYING ALOFT
WITH MIXING RATIOS BELOW 0.5 G/KG ABOVE 700 HPA SHOULD MAKE FOR
INCREASED INSTABILITY THIS AFTERNOON/EVENING.

ELEVATED CONVECTION EXPECTED SUN NIGHT OVER CENTRAL ND THEN
PRECIPITATION WILL SHIFT EAST. PRECIPITATION WILL MAINLY AFFECT
SOUTHERN ZONES. WILL ADD POPS SUN NIGHT AND MON.

LONG TERM...TUESDAY AND WEDNESDAY.
UPPER LEVEL RIDGE CONTINUES TO SHIFT EAST FROM THE SOUTHERN PLAINS
INTO THE SOUTHEAST STATES.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

TG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND FORKS ND
700 AM CDT SAT JUL 17 2010

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-181200-
WEST POLK-NORMAN-CLAY-KITTSON-ROSEAU-LAKE OF THE WOODS-
WEST MARSHALL-EAST MARSHALL-NORTH BELTRAMI-PENNINGTON-RED LAKE-
EAST POLK-NORTH CLEARWATER-SOUTH BELTRAMI-MAHNOMEN-
SOUTH CLEARWATER-HUBBARD-WEST BECKER-EAST BECKER-WILKIN-
WEST OTTER TAIL-EAST OTTER TAIL-WADENA-GRANT-TOWNER-CAVALIER-
PEMBINA-BENSON-RAMSEY-EASTERN WALSH COUNTY-EDDY-NELSON-
GRAND FORKS-GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT-
RICHLAND-WESTERN WALSH COUNTY-
700 AM CDT SAT JUL 17 2010

...SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE AREA THIS AFTERNOON
AND EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH
DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA.

.DAY ONE...TODAY AND TONIGHT

A MODERATE RISK OF SEVERE THUNDERSTORMS IS EXPECTED TODAY TO THE
RIGHT OF A LINE FROM CAYUGA TO FARGO NORTH DAKOTA TO LAPORTE
MINNESOTA. A SLIGHT RISK OF SEVERE THUNDERSTORMS IS FORECAST FOR
THE REST OF EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA. THUNDERSTORMS
WILL BE POSSIBLE ANYTIME TODAY...HOWEVER STORMS WILL MOST LIKELY
BE SEVERE FROM 3 PM CDT TO 11 PM CDT. THE STORMS WILL HAVE THE
POTENTIAL TO PRODUCE LARGE HAIL...DAMAGING WINDS AND LOCALLY HEAVY
RAIN. A FEW TORNADOES WILL ALSO BE POSSIBLE.

VERY MOIST UNSTABLE AIR WILL MOVE NORTH INTO THE NORTHERN PLAINS
TODAY. AN UPPER LEVEL DISTURBANCE WILL MOVE IN FROM THE WEST TODAY
AND PRODUCE THE THUNDERSTORMS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

HOPPES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1239 PM CDT SAT JUL 17 2010

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

1233 PM     HAIL             HENNING                 46.32N 95.44W
07/17/2010  E0.88 INCH       OTTER TAIL         MN   LAW ENFORCEMENT

&&

G2

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1243 PM CDT SAT JUL 17 2010

MNZ031-171800-
EAST OTTER TAIL MN-
1243 PM CDT SAT JUL 17 2010

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN OTTER TAIL COUNTY UNTIL
100 PM CDT...

AT 1241 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A THUNDERSTORM 8 MILES EAST OF HENNING...OR 30 MILES NORTH OF
ALEXANDRIA...MOVING TO THE EAST AT 40 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THE STORM.

THE STORM WILL BE NEAR...
WRIGHTSTOWN AROUND 1250 PM CDT.

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

G2

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
203 PM CDT SAT JUL 17 2010

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

0113 PM     HAIL             9 SW LAKE GEORGE        47.11N 95.13W
07/17/2010  E1.25 INCH       HUBBARD            MN   PUBLIC

&&

ET