National Weather Service Forecast Discussion

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FXUS65 KBOU 052046
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
245 PM MDT FRI SEP 5 2008

.SHORT TERM...POST FRONTAL UPSLOPE ACROSS ALL OF PLAINS...ROUGHLY
ABOUT A HALF KM DEEP AS NOTED BY PLATTEVILLE PROFILER. SATELLITE AND
WEB CAMS SHOWING STRATUS PERSISTING ACROSS THE PLAINS...EVEN UP INTO
THE FOOTHILLS. CEILINGS HAVE SLOWLY BEEN TRENDING UPWARD...AND TREND
SHOULD CONTINUE AS SHOWN BY BOUNDARY LAYER WIND AND HUMIDITY PROGS.
MOUNTAINS HAVE BEEN NEARLY CLOUD-FREE THOUGH SOME CUMULUS BEGINNING
TO DEVELOP. NEXT SHORTWAVE TO MOVE ACROSS WYOMING LATER THIS
EVENING. SOME QG ASCENT OVER NORTHEAST CORNER WHERE MODELS SHOW
LIGHT QPF. CURRENT WX/POPS ALREADY HAVE THIS HANDLED...WILL
CONTINUE. DESPITE LIFT...THE INSTABILITY IS LIMITED SO WILL NOT
MENTION ANY THUNDER. BOUNDARLY LAYER WIND AND HUMIDITY PROGS SUGGEST
ANOTHER BATCH OF LOW STRATUS OVER PORTIONS OF THE PLAINS AFTER 06Z.
BUT EXPECTED DRAINAGE WINDS SHOULD KEEP THE LOW STUFF EAST OF THE
URBAN CORRIDOR. WAVE AND THREAT OF ANY PRECIPITATION WILL BE
NORTHEAST OF AREA BY 12Z. MODELS SHOW DRIER AIR PUSHING INTO THE
AREA DURING THE MORNING...SO CLOUDS SHOULD BE ON THE DECREASE. BOTH
NAM AND GFS SHOW ANOTHER SHORTWAVE CLIPPING THE NORTHEAST CORNER
DURING THE AFTERNOON WITH ASSOCIATED SURFACE FRONT ACROSS ALL OF THE
PLAINS. DIV-Q VERTICAL VELOCITY PROGS SHOW SOME QG ASCENT AND THE
NAM HAS LIGHT QPF IN THAT AREA. GFS HAS NO PRECIPATION. WILL ADD
SOME LOW POPS TO THE FAR NORTHEAST CORNER. THE 18Z NAM ALSO SHOWS
SOME QPF EXTENDING FROM WASHINGTON INTO ELBERT COUNTIES. THIS QPF
COULD BE ALONG A CONVERGENCE LINE WHICH DEVELOPS BETWEEN THE
NORTHEAST AND SOUTHEAST SURFACE FLOW. FOR NOW WILL LEAVE THE POPS
CONFINED TO THE NORTHEAST CORNER. TEMPERATURE AND THICKNESS PROGS AS
WELL AS GUIDANCE SHOW HIGHS IN THE MIDDLE 70S ACROSS THE PLAINS.
THIS SEEMS ON TRACK GIVEN THE DRIER AIRMASS ADVECTING INTO AREA AND
LESS CLOUD COVER. CURRENT TEMPERATURE GRIDS LOOK GOOD...WON`T CHANCE
MUCH.

.LONG TERM...RATHER STRONG NORTHWEST FLOW ALOFT WILL REMAIN ACROSS
THE NORTHERN ROCKIES AND CENTRAL PLAINS TOMORROW NIGHT.  AN EMBEDDED
DISTURBANCE PASSING TO THE NORTH OF THE FORECAST AREA SHOULD PUSH AT
LEAST A SHALLOW COLD FRONT INTO NORTHEAST COLORADO.  THIS WILL KEEP
A THREAT OF LOW CLOUDS OVER THE PLAINS...WHILE OTHERWISE MOSTLY
CLEAR SKIES SHOULD PREVAIL.  THE WARMUP ON SUNDAY MAY ALSO BE
LIMITED BY THIS FRONTAL SURGE SO HAVE TRENDED TEMPERATURES DOWN A
BIT MORE FROM THE GOING FORECAST.

BY LATE SUNDAY INTO SUNDAY NIGHT...ANOTHER SHORT WAVE IS SCHEDULED
TO MOVE ACROSS THE NORTHERN AND CENTRAL ROCKIES IN WEST/NORTHWEST
FLOW ALOFT.  THIS ONE WILL PROVIDE MORE IN THE WAY OF UPPER LEVEL
SUPPORT AS SEEN IN THE Q-G VERTICAL MOTION FIELDS OFF THE NAM AND
GFS.  THEREFORE...THIS ONE SHOULD HAVE ANOTHER CHANCE OF
PRECIPITATION SIMILAR TO THIS LAST FRONT.  AGAIN...THE MAIN THREAT
IS SHAPING UP FOR THE NORTHEAST CORNER OF THE STATE.  THE COLD FRONT
ASSOCIATED WITH THIS DISTURBANCE WILL PROVIDE FOR ANOTHER COOL DAY
MONDAY.  HOW COOL WILL DEPEND ON HOW MUCH CLOUDS WILL BE AROUND BUT
SEEMS PRUDENT AT THIS POINT TO LOWER HIGH TEMPERATURES INTO THE MID
60S FOR NOW ESPECIALLY CONSIDERING TODAYS UNSEASONABLY COOL TEMPS.

A WARMUP IS STILL EXPECTED TUESDAY AND WEDNESDAY...BEFORE THE NEXT
SHORT WAVE AND COLD FRONT ARRIVES WITH A CHANCE OF PRECIPITATION
THURSDAY.

&&

.AVIATION...MVFR CEILINGS TO CONTINUE TO IMPROVE THROUGH 03Z...WITH
VFR CONDITIONS PREVAILING THROUGH SATURDAY. WEAK DISTURBANCE TO MOVE
ACROSS NORTHEAST PLAINS AFTER 03Z...ANY SHOWERS TO REMAIN WELL NORTH
AND EAST OF THE AREA AIRPORTS. SOME LOW STRATUS TO REDEVELOP ACROSS
PLAINS AFTER 06Z...SHOULD STAY EAST OF DIA. ANOTHER DISTURBANCE TO
MOVE ACROSS NORTHEAST PLAINS AFTER 18Z...ANY SHOWERS WILL BE WELL
NORTHEAST OF THE AREA AIRPORTS. SURFACE WINDS TO SHIFT TO THE SOUTH
BY 06Z...THEN NORTH TO NORTHEAST AFTER 18Z.

&&

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

$$

D-L/BARJENBRUCH

NWS BOU Office Area Forecast Discussion