Special Weather Statement, NWS Denver/Boulder, CO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
300 PM MDT MON JUL 18 2011

.SHORT TERM...AS LIKE YESTERDAY...CONVECTION CONTINUES TO DEVELOP
OVER THE MOUNTAINS AND FOOTHILLS WITH STEERING FLOW TO THE NNE. THE
HIGH PRESSURE IS STILL CENTERED OVER THE CENTRAL PLAINS WITH MUCH OF
THE EASTERN PLAINS OF COLORADO STILL CAPPED UNDER THE BIG HIGH.
INTEGRATED PRECIPITABLE WATER TRENDS FROM GPS HAVE INCREASED OVER
THE FRONT RANGE WITH PW READINGS JUST OVER AN INCH.  MOST OF THE
STORMS SHOULD REMAIN OVER THE FOOTHILLS...BUT THEY ARE CLOSE ENOUGH
THAT AN OUTFLOW BOUNDARY COULD KICK UP AN ISOLATED STORM OVER
WESTERN PORTIONS OVER THE URBAN CORRIDOR.

FOR TUESDAY...THE HIGH WILL SHIFT EASTWARD AS THE UPPER TROF NOW OFF
THE NRN CALIFORNIA COAST MOVES INLAND.  THIS WILL ALLOW THE STORMS
TO MOVE OFF THE FOOTHILLS AND ACROSS PORTIONS OF THE NORTHEAST
PLAINS BY LATER TUESDAY AFTERNOON. THE STEERING FLOW WILL BE
NORTHEAST AND ALLOW BETTER PROPAGATION OVER THE PLAINS. HAVE ADDED
POPS TO THE GRIDS TO THE PLAINS ADJACENT FOR TUESDAY. HAVE ALSO
LOWERED TEMPS A FEW DEGREES. MOS GUIDANCE CONTINUES TO BE TOO WARM
IN MOST LOCALES.

.LONG TERM...SOUTHWEST FLOW ALOFT WILL CONTINUE OVER THE STATE
TUESDAY NIGHT AS THE UPPER RIDGE STAYS OVER THE MISSISSIPPI VALLEY.
SHOULD CONTINUE SEEING SCATTERED THUNDERSTORMS OVER THE PLAINS
TUESDAY EVENING WITH A FEW ISOLATED STORMS LASTING PAST MIDNIGHT
OVER THE FAR EASTERN PLAINS.

A WEAK DISTURBANCE ALOFT WILL PUSH A WEAK FRONT ACROSS NORTHEASTERN
COLORADO WEDNESDAY. AN INCREASE IN MOISTURE WILL BE MOVING IN THE
SOUTHWEST FLOW ALOFT FROM THE CURRENT TROPICAL STORM DORA WEDNESDAY
AND THURSDAY...INCREASING PRECIPITABLE WATER VALUES. THIS
DISTURBANCE AND ASSOCIATED FRONT WILL COMBINE WITH THE INCREASED
MOISTURE TO BRING AT LEAST SCATTERED CONVECTIVE ACTIVITY TO
NORTHEASTERN COLORADO WEDNESDAY AND THURSDAY. INCREASED POPS BOTH
DAYS TO REFLECT THIS PATTERN. BOTH DAYS WILL SEE TEMPERATURES COOL
BACK TOWARD AVERAGE...IN THE UPPER 80S TO LOWER 90S FOR THE PLAINS
AND IN THE 70S AND LOW 80S FOR THE MOUNTAINS. THE THREAT WILL REMAIN
TO BE LOCALLY HEAVY RAINFALL AS FREEZING LEVELS STAY QUITE HIGH WITH
THE RIDGE NEARBY.

DID NOT CHANGE THE FORECAST PAST THURSDAY...WITH 10-20 PERCENT POPS
DURING THE AFTERNOONS AND EVENINGS THROUGH THE WEEKEND AND
TEMPERATURES WARMER THAN AVERAGE AS THE UPPER RIDGE BEGINS TO MOVE
BACK WEST AND OVER THE REGION. AS THE MOIST MONSOONAL FLOW CONTINUES
OVER THE STATE...THE MAIN THREAT FROM SHOWERS IS GOING TO BE LOCALLY
HEAVY RAINFALL.

&&

.AVIATION...STILL NOT EXCITED ABOUT ANY STORMS OVER THE LOCAL
TERMINALS THROUGH THIS EVENING. HOWEVER GIVEN THE PROXIMITY OF
STORMS IN THE FOOTHILLS...THEY COULD KICK OUT A BOUNDARY WHICH COULD
IGNITE STORMS OVER WESTERN PORTIONS...INCLUDING BJC. WILL MAINTAIN
THE VCTS AT BJC BUT KEEP APA/DEN DRY. EXPECT AN INCREASE IN STORM
COVERAGE ON TUESDAY AS STEERING FLOW TURNS SW TO NE AND MORE
MOISTURE OVER THE URBAN CORRIDOR. HAVE ALREADY INTRODUCED A POP30
FOR KDEN LATER TUESDAY AFTN.

&&

.HYDROLOGY...SCATTERED THUNDERSTORMS WITH SOME TRAINING OF ECHOES
WILL KEEP A SMALL THREAT FOR FLASH FLOODING OVER THE EAST SLOPES
THIS AFTERNOON AND EVENING IF STORMS CONTINUE TO FLOW OVER THE SAME
AREAS. THE THREAT FOR FLASH FLOODING OVER THE FOOTHILL BURN SCARS IS
ALSO LOW TODAY WITH MOST OF THE STORMS STAYING JUST WEST OF THE BURN
AREAS. HOWEVER...A SLOW MOVING STORM CAN NOT BE RULED OUT FOR THE
BURN AREAS.

SOUTH PLATTE RIVER CONTINUES TO RUN HIGH OVER NORTHEAST COLORADO
WITH FLOOD ADVISORIES CONTINUING FROM BALZAC TO JULESBURG FOR THE
NEXT SEVERAL DAYS.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...NONE.

&&

ENTREKIN/KRIEDERMAN