Flash Flood Warning 8, NWS Grand Junction, CO

COZ001>012-014-015-017>023-UTZ023>027-060730-

WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
128 PM MDT TUE AUG 5 1997

IT IS A CONFUSING WEATHER SITUATION IN MY OPINION.  BASED ON SATELLITE
MOVEMENTS...ALL MODELS SEEMED TO BE CORRECT YESTERDAY IN TAKING THE LOW
NORTHWARD INTO EASTERN IDAHO AND SOUTHWEST MONTANA.  THEY ALL THEN MOVED
THE LOW TO THE SOUTHEAST WITH A BIG ASSOCIATED VORTICITY AREA MOVING
INTO WESTERN WY BY THIS EVENING.  THAT TREND STILL REMAINS ON THE LATEST
MODEL RUNS AND LOOKS OK.  AT THE SAME TIME...THEY KEPT LOTS OF MOISTURE
AROUND ESPECIALLY OVER THE NORTHERN PORTION OF THE CWA ALTHOUGH SOME
DRYING IS INDICATED. SATELLITE...HOWEVER...IS ALREADY SHOWING GOOD
DRYING OVER MOST OF UTAH MOVING INTO OUR AREA.  GRANTED THE MOISTURE
SEEN ON SATELLITE IN THE SALT LAKE CITY AREA DOES CORRESPOND WITH VORT
LOBE/TROUGH SEEN ON MODELS. THIS SHOULD ARRIVE IN NORTHWEST CO/NORTHEAST
UT EARLY THIS EVENING AND COULD BE ENOUGH TO KICK OFF SOME HEAVY RAIN SO
EXPECT THE FFA SHOULD CONTINUE THIS EVENING.

CONFUSION COMES WITH THE 24 HOUR PATTERN.  THE MODELS BRING THE LOW INTO
NORTHEAST CO...AS I WOULD EXPECT GIVEN THE 300 MB FLOW...BUT THEY MOVE
THE MAJOR VORT LOBE ASSOCIATED WITH THIS ALMOST STRAIGHT SOUTH.  THIS
DOES NOT MAKE SENSE TO ME.

BOTTOM LINE...I EXPECT QUITE A BIT OF DRYING TONIGHT AND WED OVER MOST
OF OUR CWA MAINLY TO THE SOUTH OF THE TAVAPUTS PLATEAU (ZONE 3) WITH
CONVECTION BUILDING UP DURING THE DAY MAINLY OVER THE MOUNTAINS AND
TEMPS A BIT CLOSER TO NORMALS.  SOME EXTRA MOISTURE IS LIKELY TO REMAIN
OVER THE NORTHERN SECTION SO A BIT MORE CLOUDINESS IS LIKELY BUT STILL
EXPECT GENERALLY PARTLY CLOUDY MORNINGS.

RWJJ