NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NWS DENVER COLORADO
AFDDEN 230 PM MDT TUE JUL 20 1999
VERY PERSISTENT UPPER LEVEL RIDGE OVER MUCH OF THE COUNTRY WILL
REMAIN IN PLACE FOR SEVERAL MORE DAYS. COLORADO WL BE LEFT UNDER
WEAK SLY FLOW ALOFT WHICH WL PROBABLY ALSO BE QUITE MOIST. THE
SOUTHWEST U.S. MONSOON IS WELL ESTABLISHED...AND AS LONG AS THE UPR
RIDGE IS IN PLACE...WL BE CONTG. PINNING DOWN DETAILS LIKE
LOCATIONS AND PROBABILITIES OF HEAVY RAINFALL CAN'T BE DONE ON THIS
FCST TIMESCALE...SO AM LEFT WITH THE OPTION OF 20-40 PERCENT CHANCES
OF AFTN AND EVENING SHOWER ACTIVITY...PRIMARILY OVR THE MTNS AND
FTHLS.
TDA'S CONVECTION IS BEING SUPPRESSED BY THE SUBSIDENCE BEHIND A
SHORT WAVE FEATURE THAT PASSED OVR THE NRN HALF OF THE STATE LATE
THIS MRNG. THE LATEST ACARS SOUNDINGS FROM DENVER INTL ARPT ARE
ALSO SHOWING SOME WARMING ARND 450 MB...HELPING TO KEEP THE AFTN CU
PRETTY FLAT UP TO THIS POINT.
AMONG THE DETAILS THAT I CAN ATTEMPT TO USE FOR TMRW'S FCST IS THAT
THE NGM 700 MB THETA-E RIDGE WL BE STRONGER TMRW AFTN THAN TDA.
THIS WL LEAD ME TO GO WITH 30 PERCENT CHANCE OF AFTN AND EVENING
SHOWERS.
AS THE PREVIOUS SHIFT MENTIONED...THE MRF WANTS TO DRY THINGS OUT
AFTER ABOUT 3 DAYS...BUT WL NOT ACCEPT THIS SINCE THE PERSISTENT
MONSOON WL KEEP BRINGING MOISTURE INTO THE STATE FOR ADDITIONAL AFTN
SHOWERS EACH DAY. KDRBY
.DEN...NONE.