Flood in Colorado, August 7, 2001

WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
200 PM MDT TUE AUG 7 2001

FLASH FLOOD WATCH CONTINUES THIS AFTERNOON AND TONIGHT FOR ALL OF THE
CWA EXCEPT NORTHEAST UTAH.

ATMOSPHERE REMAINS VERY MOIST AND AN EXTENSIVE CLOUD COVER IS
PRESENT OVER MOST OF WESTERN COLORADO AND EASTERN UTAH. PER THE
ETA, THE PESKY UPPER WAVE OVER THE WY/CO BORDER SHOULD DRIFT SLOWLY
SOUTHWARD THROUGH WEDNESDAY. THIS PICTURE SUGGESTS HEAVY RAIN
POTENTIAL FOR WESTERN COLORADO AND SOUTHEAST UTAH. THE AVN SOLUTION
IS SLIGHTLY DIFFERENT OVER THE NEXT FEW DAYS, KEEPING THE WAVE A
LITTLE FARTHER NORTH BEFORE DROPPING IT SOUTHWARD ON WEDNESDAY. IN
THE WEAK TO NON-EXISTENT FLOW ALOFT, I DONT FEEL EITHER MODEL HAS
A REAL GOOD HANDLE OF THE MOVEMENTS OF ALL OF THE SHORTWAVES OVER
THE SOUTHWEST U.S.

GENERAL IDEA OF BOTH MODELS IS FOR THE WAVE TO SLIP SOUTHWARD,
TIMING ASIDE. WITH THE ATMOSPHERE THIS MOIST, ITS NOT GOING TO TAKE
MUCH ENERGY FOR CONVECTION...ESPECIALLY IN THE HIGHER TERRAIN.
PRECIPITABLE WATER WAS 1.28 ON THE KGJT 12Z SOUNDING. SOILS ARE
SATURATED IN MANY AREAS FROM STORMS OVER THE PAST FEW DAYS, SO I
FEEL THE FLASH FLOOD IS IN ORDER.

MODELS SHOW A RE-CENTERING OF A HIGH PRESSURE RIDGE OVER AZ/CA.
THIS SHOULD CHANGE OUR UPPER FLOW TO A NORTHERLY DIRECTION. HOWEVER,
WITH ABUNDANT MOISTURE OVER MUCH OF THE WEST, THIS MAY NOT DRY US
OUT SIGNIFICANTLY. SO, WILL KEEP A BROADBRUSH CHANCE OF SHOWERS IN
THE FORECAST.

WITH ALL THE CLOUD COVER, HIGH TEMPERATURES WILL BE SLIGHTLY COOLER
THAN THE PAST FEW DAYS. BUT, DEWPOINTS WILL REMAIN HIGH...AND
MUGGY CONDITIONS WILL CONTINUE. BA

EXTENDED: SUBTROPICAL SUMMER PATTERN CONTINUES INTO NEXT WEEK WITH
THE DEVIL IN THE NEBULOUS DETAILS.  LATEST MRF HAS THE UPPER HIGH
TO THE SW ON FRIDAY PRODUCING LIGHT NW FLOW OVER THE REGION THIS
WOULD GENERALLY FAVOR THE NORTHERN MTNS WITH THUNDERSTORM ACTIVITY.
AS PER MRF/EC/UK...RIDGE PROGRESSES TO OVERHEAD BY SUNDAY AND KEEPS
IT IN THE VICINITY THRU TUESDAY...LESS PROGRESSION THAN PREVIOUS MRF.
THIS WOULD KEEP TEMPERATURES ABOVE NORMAL AND GENERALLY POP FAVOR
THE SOUTHERN MTNS. SLOW STORM MOTION KEEPS THE POTENTIAL FOR FLASH
FLOODING EVENTS.  RAMEY

.GJT...FLASH FLOOD WATCH FOR THIS EVENING FOR ALL OF WESTERN
   COLORADO...AND IN EASTERN UTAH THE COUNTIES OF SAN JUAN...GRAND
   AND SOUTHERN UINTAH.