Flood in Utah, July 8, 2001

WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
315 AM MDT SUN JUL 8 2001

ACTIVE NIGHT OVER NORTHWEST COLORADO WHERE TRAILING SHORT WAVE KEEPS
GENERATING NUMEROUS THUNDERSTORM CELLS.  SUFFICIENT SPEED SHEAR FOR
ISOLATED CELLS TO BE STRONG AND PRODUCE BRIEF HEAVY RAIN.  CONVECTIVE
ACTIVITY WEAKENING DURING THE PAST HOUR AND THIS TREND OUGHT TO HOLD
FOR THE REMAINDER OF THE NIGHT.

COUNTY WARNING AREA EXPECTED TO BE IN A REGION OF SUBSIDENCE FOR
MOST OF THE DAY.  DEEPEST MOISTURE PLUME REMAINS OVER WESTERN
UTAH/EASTERN NEVADA.. WHILE DEEP SOUTH SOUTHEAST FLOW OVER SOUTHWEST
COLORADO ADVECTS DRIER AIR.  MODEL DATA INDICATE THAT PRECIPITABLE
WATER WILL DROP BACK UNDER ONE INCH THIS AFTERNOON.  HIGHEST WATER
CONTENT WITHIN FORECAST AREA ACROSS THE NORTHERN ZONES.. AND EXPECT
THIS AREA TO HAVE THE BEST POTENTIAL FOR CONVECTIVE ACTIVITY BY MID
AFTERNOON.  ISOLATED STORMS WILL BE RELATIVELY STRONG DUE TO LIMITED
SPEED SHEAR (AROUND 25 KNOTS IN THE 700 TO 300 MB LAYER).

BOTH ETA AND AVN MODEL INCREASE MOISTURE ON MONDAY AFTERNOON.  AT
THIS TIME.. HAVE SOME DOUBT AS HIGH PRESSURE STAYS PLANTED OVER
OKLAHOMA AND KANSAS.  ONE SIGNIFICANT MODEL DIFFERENCE.. THE AVN
SOLUTION KEEPS RIDGE AXIS TILTED BACK TO THE NORTHERN INTERMOUNTAIN
REGION.. WHILE THE ETA FLATTENS THE RIDGE AND SOMEWHAT PROGRESSIVE
WITH SHORT WAVES.  AVN THE PREFERRED SOLUTION.. AND THIS !WOULD LIMIT
THE AMOUNT OF MOISTURE FROM OUR WEST SHIFTING TOWARD WESTERN
COLORADO.  FRISBIE

WESTERN COLORADO AND EASTERN UTAH EMERGENCY MANAGERS SHOULD MAINTAIN
A NORMAL LEVEL OF WEATHER AWARENESS TODAY.

.GJT...NONE.