Severe Thunderstorm Warning 169, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
310 PM CDT WED JUL 22 1999

FORECAST PROBLEM FOR TONIGHT IS PCPN. LATEST VIS SATELLITE IMAGERY HAS
AC AND CI WITH EMBEDDED TSRA ALONG SPEED CONVERGENCE BOUNDARY THROUGH
CENTER OF CWFA. LATEST ADAP HAS LIS OF AROUND -10 WITH A SFC MOISTURE
CONVERENCE MAX NEAR DVL AND ABOUT A 2 DEGREE CAP. MODELS SIMILAR IN
TREATMENT OF SHORTWAVE AS IT LIFTS N FROM SD THROUGH ND SIDE OF CWFA BY
06Z. STILL PREFER ETA SOLUTION OVER OTHER MODELS SINCE IT HAS HAD THE
BEST ACCURACY AND CONSISTENCY OVER THE PAST FEW DAYS. POTENTIAL REMAINS
FOR SVR OVER CWFA AS THE WAVE MOVES THROUGH. THEREFORE...WILL LEAVE
EVENING TSRA WITH POSSIBLE SVR IN FORECAST FOR THIS EVENING.

FORECAST PROBLEM FOR 2ND THROUGH 4TH PERIOD IS TEMPS. MODELS CONTINUE
TO KEEP 500MB RIDGE OVER NORTHERN PLAINS WITH SHORTWAVES RIDING THROUGH.
HOWEVER...BEST UVV REMAINS W OF CWFA AS A LOW PRESSURE SYSTEM DEVELOPS
IN E MT BY SAT. GOOD WAA REMAINS AHEAD OF THIS NEXT LOW PRESSURE
SYSTEM...KEEPING HOT AND HUMID CONDITIONS OVER THE CWFA INTO SAT.

EXTENDED FORECAST...AFTER VERY WARM AND SULTRY SATURDAY...EXPECT
SOUTHWARD EXPANDING WESTERLIES TO SWEEP FAIRLY SIGNIFICANT COLD FRONT
ACROSS THE REGION SUNDAY ACCOMPANIED BY THE POTENTIAL FOR RATHER HEFTY
THUNDERSTORMS. COOLER AND DRIER CONDITIONS SHOULD THEN FOLLOW IN ITS
WAKE FOR MONDAY AND TUESDAY.

.FGF...NONE

NG/BERG

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052-053-221915-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1131 AM CDT THU JUL 22 1999

...SEVERE THUNDERSTORMS ARE EXPECTED ACROSS EASTERN NORTH DAKOTA AND
NORTHWEST AND WEST CENTRAL MINNESOTA THIS AFTERNOON AND EVENING...

SYNOPSIS...UNSTABLE AIR WILL REMAIN IN PLACE FOR THE REMAINDER OF
THE AFTERNOON...WITH DEW POINTS IN THE LOWER 70S AND TEMPERATURES
OF AROUND 90. AN UPPER LEVEL TROUGH AND WEAK SURFACE COLD FRONT
WILL APPROACH THE REGION THIS AFTERNOON...AND PASS THROUGH THE AREA
BY MIDNIGHT.

AREA OF CONCERN...A MODERATE RISK OF SEVERE THUNDERSTORMS IS
FORECAST FOR AREAS OF EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
FROM COOPERSTOWN TO MAYVILLE TO BEMIDJI AND POINTS NORTH. SOUTH OF
THIS LINE A SLIGHT CHANCE OF SEVERE THUNDERSTORMS IS FORECAST.

TIME...BETWEEN 4 PM AND MIDNIGHT.

TYPE OF HAZARD...MAINLY STRAIGHT LINE WIND DAMAGE...LARGE HAIL AND
ISOLATED TORNADOES.

KELLENBENZ/BRAZZELL