Flood in Utah, August 13, 2001

WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
200 PM MDT MON AUG 13 2001

NOT MUCH CHANGE TO PREVIOUS FORECAST PACKAGE. THINGS ARE DEVELOPING
ABOUT AS EXPECTED. ONLY CONCERN AT THIS TIME IS THE AREA NORTH OF
OUR FLASH FLOOD WATCH.  SOME OF THE HIGHEST PRECIP AMOUNTS INDICATED
BY WSR-88D IN OUR CWA SO FAR THIS AFTERNOON HAVE BEEN IN THE
NORTHEAST FLAT TOPS AND SOUTHERN PART OF ADJACENT ZONE 4 OF THE GORE
RANGE. THIS AREA DID NOT HAVE AS MUCH PRECIP LAST WEEK AS IN TODAYS
FLASH FLOOD WATCH AREA...THUS SOILS IN THE ZONES NORTH OF THE FLASH
FLOOD WATCH SHOULD BE ABLE TO HANDLE THE RAIN WITH MINIMAL POTENTIAL
FOR RUNOFF PROBLEMS. NONETHELESS...THIS BORDERLINE SITUATION BEARS
WATCHING FOR POSSIBLE EXTENSION OF THE WATCH...AS THIS LOCATION IS IN
AN APPARENT AREA OF HIGH LEVEL DIFLUENCE AND GOOD UPPER LEVEL
VENTILATION.

TREND FOR LESS MOISTURE OVER OUR CWA TOMORROW STILL LOOKS GOOD
AS A RESULT OF NORTHWEST FLOW WHICH TENDS TO DRY THINGS OUT THIS TIME
OF YEAR. SHOULD BE A BIT BREEZY IN MOST MOUNTAIN ZONES AND PERHAPS
ALSO SOME VALLEYS IN NORTH AS PRESSURE GRADIENT WILL HAVE INCREASED.
MAX TEMPS TUESDAY LIKELY TO BE ABOUT SAME AS TODAY...DESPITE MORE
SUN...AS SOME WEAK LOW LEVEL COOLING LIKELY WITH THE NW FLOW.

NW FLOW ALOFT CONTINUES WEDNESDAY AS UPPER RIDGE REMAINS TO THE WEST.
THOUGH EVEN LESS CONVECTION EXPECTED FOR WEDNESDAY WHICH SHOULD
RESULT IN EVEN MORE SOLAR INPUT...MAX TEMPS WEDNESDAY SHOULD ONLY
REBOUND A LITTLE OVER TUESDAY IN MOST ZONES.

PRINGLE

EXTENDED: WITH THE HIGH PRESSURE CENTER LOCATED SOUTHWEST OF THE
FORECAST AREA...DRIER NORTHWEST FLOW WILL CONTINUE THROUGH MOST
OF THE PERIOD.  THIS IS HANDLED WELL IN THE FORECAST AND WILL LEAVE
DAYS 3-6 AS IS.  WILL KEEP SLIGHT CHANCE OVER MOUNTAINS FOR
THU/FRI AND DRY OVERALL FOR SAT/SUN. THE RIDGE AXIS SHIFTS SLOWLY
TOWARDS THE EAST DURING THE PERIOD WITH THE FLOW BECOMING SOUTHWEST
LATE SUNDAY/EARLY MONDAY. THIS WILL OPEN THE DOOR FOR ANOTHER SURGE
OF MONSOONAL MOISTURE. THEREFORE WILL INCREASE CHANCES ON MONDAY...
ESPECIALLY OVER THE SOUTH. EH

.GJT...FLASH FLOOD WATCH UNTIL MIDNIGHT FOR SOUTHERN TWO THIRDS OF
OUR AREA...INCLUDING COZ003-006>012-14-17>23 AND UTZ022-025-027>029.