Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 200839
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
239 AM MDT WED AUG 20 2014

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 238 AM MDT WED AUG 20 2014

SW FLOW ALOFT WILL BE OVER THE AREA TODAY AND TONIGHT WITH STILL
SOME MONSOON MOISTURE AFFECTING THE AREA.  PRECIPITABLE WATER VALUES
BY AFTN WILL BE AOA AN INCH OVER NERN CO WITH LOWER VALUES OVER THE
MTNS.  OVERALL WILL KEEP SCT TSTMS IN THE MTNS WITH WIDELY SCT
ACTIVITY ACROSS THE REST OF THE AREA.  CAPES WILL ONLY BE IN THE 500-
1000 J/KG SO THREAT OF SVR IS LOW HOWEVER MAY SEEM A FEW SPOTS
RECEIVE HEAVIER RAINFALL OVER THE PLAINS WHERE PRECIPITABLE WATER
VALUES WILL BE THE HIGHEST ALTHOUGH STORMS WILL BE MOVING RATHER
QUICKLY. AS FOR HIGHS WILL KEEP READINGS MAINLY IN THE UPPER 80S
TO LOWER 90S ACROSS NERN CO.


.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 1200 AM MDT WED AUG 20 2014

THURSDAY AND THURSDAY NIGHT...A PERSISTENT SOUTHWESTERLY FLOW
ALOFT WILL BE OVER THE STATE WITH AN UPPER TROUGH OVER THE GREAT
BASIN AND A RIDGE OF HIGH PRESSURE OVER THE SERN U.S. SUBTROPICAL
MOISTURE IS NOT AS WELL ESTABLISHED OVER CO WITH THE BEST CHC OF
TSTMS EXPECTED OVER THE HIGHER TERRAIN IN THE AFTN/EVNG...WITH
LESSER POPS OVER THE NERN PLAINS. NAM12 SOUNDINGS AT DENVER
INDICATE PW VALUES AROUND .6 TO .7 INCHES WITH STORM MOTIONS
AROUND 15 MPH. MAIN THREAT FM THE STORMS WILL CONTINUE TO BE BRIEF
HEAVY RAIN...BUT OVERALL FLOODING THREAT WILL BE IN THE LOW TO
MODERATE RANGE.

FRIDAY AND FRIDAY...THE GFS TRIES TO LIFT THE TROUGH FM THE GREAT
BASIN INTO CO...WHILE THE ECMWF AND NAM12 HOLD THE SYSTEM BACK.
THE PLUME OF SUBTROPICAL MOISTURE APPEARS TO BE BETTER ESTABLISHED
OVER NERN CO. NAM12 SOUNDINGS ON FRIDAY INCREASE THE PW VALUES
BACK TO AROUND ONE INCH...SO THE STORMS THAT DEVELOP SHUD PRODUCE
HEAVIER RAIN SHOWERS AND INCREASE THE POTENTIAL FOR FLOODING. THE
OVERALL STORM MOTIONS HOWEVER WILL BE FASTER (20-25 MPH). AS A
RESULT THE FLASH FLOOD RISK MAY NOT CHANGE MUCH FM THURSDAY.
OVERALL THE COVERAGE AND INTENSITY OF THE STORMS SHOULD INCREASE
...ASSUMING THE INCREASING CLOUD COVER DOES NOT OFFSET THE HEATING
TOO MUCH.

ON SATURDAY AND SATURDAY NIGHT...THE FLOW ALOFT REMAIN
SOUTHWESTERLY WITH THE MDLS DROPPING ANOTHER TROUGH FM THE
PACIFIC NORTHWEST ANDS INTO CENTRAL AND SRN IDAHO BY 12Z
SATURDAY. THE MDLS THEN DRAG THE TROUGH AXIS ACROSS
MONTANA/WYOMING LATE SATURDAY AND SATURDAY NIGHT. SHOULD AGAIN SEE
A DECENT COVERAGE FOR THUNDERSTORMS ESPECIALLY NORTH OF I-70 TO
THE CO/WY LINE SATURDAY NIGHT. WL INCREASE THE POPS IN THOSE AREAS
IN THE GRIDS.

SUNDAY AND SUNDAY NIGHT...A COLD FRONT ASSOCIATED WITH THE TROUGH
SHIFTING TO THE NORTH AND EAST OF COLORADO WILL PUSH THROUGH THE
CWFA BY SUNDAY MORNING. THE COOLER AMS SHOULD HELP CAP MUCH OF THE
DEEP CONVECTION OVER THE NERN PLAINS WITH THE BEST CHC OF TSTMS
OVER THE MOUNTAINS AND PALMER DIVIDE SUNDAY AFTN AND EVENING.

MONDAY THROUGH TUESDAY...THE MDLS SOLUTIONS CONTINUE TO DIFFER SO
HARD TO SETTLE ON ONE SOLUTION WITH THE SYNOPTIC SCALE FEATURES
COMPLETELY OUT OF PHASE WITH ONE ANOTHER OVER THE WRN U.S. FOR
NOW THE OVERALL TREND WL BE TO KEEP A CHANCE OF TSTMS IN THE
MOUNTAINS WITH LESSER POPS OVER THE NORTHEASTERN PLAINS EACH
AFTN/EVNG.

&&

.AVIATION...(FOR THE TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 1200 AM MDT WED AUG 20 2014

WIDELY SCT TSTMS WILL BE POSSIBLE BETWEEN 21Z AND 00Z WITH GUSTY
OUTFLOW WINDS TO 40 MPH POSSIBLE FM ANY STORM.  WINDS EARLY THIS
MORNING WERE LIGHT SWLY AND WILL BECOME MORE VARIABLE IN NATURE
AFTER SUNRISE. BY MIDDAY THEY WILL BECOME LIGHT ELY HOWEVER BY
21Z EXPECT WINDS MAY BECOME MORE WSW AS OUTFLOW BOUNDARIES MOVE
ACROSS. FOR THIS EARLY EVENING WILL WINDS MAY BECOME MORE WNW FOR
A FEW HOURS BUT THEN BECOME SSW BY 06Z.

&&

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

$$

SHORT TERM...RPK
LONG TERM...COOPER
AVIATION...RPK


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