FXUS65 KPUB 292235
AFDPUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
335 PM MST SUN NOV 29 2009

.SHORT TERM...
(TONIGHT AND MONDAY)

CURRENTLY...UPPER LOW SPINNING WELL SOUTH OF THE MEXICAN BORDER OVER 
THE GULF OF CALIFORNIA THIS AFTERNOON...WITH DRIER AIR MASS 
SPREADING SOUTH ACROSS COLORADO. SOUTHWARD SHIFT OF THE LOW REALLY 
LIMITED SNOW CHANCES ACROSS THE AREA...AS BEST LIFT REMAINED OVER NM 
AND THE TEX PANHANDLE. ONLY AREA THAT SAW MORE THAN FLURRIES WAS 
OVER/NEAR THE EASTERN SAN JUANS...WHERE 2 TO 4 INCHES FELL EARLIER 
TODAY. AS OF 21Z...CLEARING SKIES HAVE SPREAD SOUTH OVER ALMOST ALL 
THE FORECAST AREA...WITH ONLY SOME HIGH LEVEL CLOUDS LINGERING ALONG 
THE NM BORDER. 

TONIGHT...REMOVED SNOW CHANCES FROM MOST AREAS...LEAVING ONLY SOME 
ISOLATED POPS OVER THE EASTERN SAN JUANS WHERE A -SHSN OR TWO COULD 
DRIFT NORTHWARD OUT OF NM THIS EVENING. WITH CLEARING SKIES AND DRY 
AIR MASS ADVECTING IN...OVERNIGHT LOWS WILL BE SEASONABLY CHILLY 
WITH TEENS AND 20S MOST AREAS...WHILE HIGH MOUNTAIN VALLEYS DROP 
INTO THE SINGLE DIGITS.  

MONDAY...UPPER LOW REMAINS FAR TO THE SOUTH OVER MEXICO...WITH WEAK 
FLOW ALOFT ACROSS THE AREA THROUGH THE DAY. WITH WARMER 700 MB TEMPS 
OVER THE NRN ROCKIES...WEAK NLY GRADIENT WILL PROVIDE SOME MODEST 
WARM ADVECTION...ALLOWING MAX TEMPS TO CLIMB INTO THE 40S AND 50S 
MOST AREAS...WITH 30S LIMITED TO HIGHER MOUNTAIN ZONES. COULD BE A 
FEW HIGH LEVEL CLOUDS ALONG THE NM BORDER BY AFTERNOON...BUT VAST 
MAJORITY OF THE AREA WILL ENJOY SUNSHINE AND A NICE LATE FALL DAY

.LONG TERM...
(MONDAY NIGHT THROUGH SUNDAY)

MONDAY NIGHT AND TUESDAY...MODELS AGREE ON KEEPING THE UPPER CLOSED 
LOW WELL SOUTH OF COLORADO...KEEPING CONDITIONS ACROSS THE CWA 
MOSTLY CLEAR. THIS WILL LEAD TO CLEAR AND COLD CONDITIONS MON 
NIGHT...THEN MAX TEMPS IN THE MID 50S FOR THE LOWER ELEVATIONS TUE. 
NAM AND GFS MODELS CONTINUE TO SHOW A SFC COLD FRONT DROPPING DOWN 
THE E PLAINS TUE AFTN...REACHING THE PALMER DVD BETWEEN 16-18Z...BUT 
AT LEAST INITIALLY THE FRONT LOOKS TO BE DRY.

TUESDAY NIGHT THROUGH FRIDAY...LARGE UPPER LOW DROPS DOWN OUT OF 
CANADA AND CROSSES THE DAKOTAS AND MINNESOTA TUE NIGHT AND WED. THIS 
PROVIDES THE REINFORCING COLD NORTHERLY SURGE FOR THE E HALF OF 
COLORADO BEGINNING TUE NIGHT. NW FLOW ALOFT REMAINS IN PLACE THRU 
FRI...WHILE AT THE SAME TIME LLVL FLOW SHIFTS TO A MORE UPSLOPE 
DIRECTION. SHALLOW UPSLOPE FLOW SHOULD KEEP A SLIGHT THREAT FOR SOME 
LIGHT PCPN OVER THE PALMER DVD AND RAMPART RANGE...WETS AND N 
SANGRES...AND AT LEAST FOR TUE NIGHT AND WED OVER THE CENTRAL MTS AS 
WELL. ONGOING POP GRIDS HAD ISOLATED THREAT OVER THE SW MTS AND S 
SANGRES AS WELL...BUT LATEST MODEL RUNS JUST DO NOT SUPPORT THIS AND 
PULLED POPS IN THOSE AREAS. EXPECT MAX TEMPS WED THRU FRI TO HOVER 
IN THE MID 30S TO LOWER 40S.

SATURDAY AND SUNDAY...LATEST MODEL RUNS OF THE ECMWF AND GFS ARE NOW 
STARTING TO LOOK A BIT MORE ALIKE CONCERNING THE NEXT POTENTIAL LOW 
PRES TROUGH TO AFFECT THE REGION. GFS INDICATES ZONAL FLOW ALOFT FOR 
THE STATE ON SAT AHEAD OF THE APPROACHING TROUGH...WHILE THE EXMWF 
FORECASTS A RIDGE. BOTH SOLUTIONS WOULD RESULT IN WARMER DRY 
CONDITIONS FOR THE STATE THRU THE FIRST HALF OF THE DAY SAT. GFS 
DROPS THE TROUGH DOWN INTO THE GREAT BASIN STARTING SAT 
NIGHT...WHICH WOULD BRING A THREAT OF PCPN BACK TO THE HIGHER 
TERRAIN LATE SAT AND THROUGH SUN. ECMWF PAINTS A SLOWER PROGRESSION 
OF THIS FEATURE...KEEPING THE TROUGH UP OVER THE PAC NW A BIT 
LONGER...BUT AT LEAST IT IS NOW SHOWING THIS TROUGH...AS OPPOSED TO 
BEING TOTALLY OUT OF PHASE WITH THE GFS AS IT WAS 24 HRS AGO. GIVEN 
SUCH UNCERTAINTY...MAINTAINED SOMEWHAT COOL TEMPS AND WIDESPREAD 
ISOLATED POPS...AND WILL HAVE TO START ADJUSTING OVER THE NEXT 
COUPLE OF DAYS. MOORE

&&

.AVIATION...
WITH UPPER LOW SHIFTING WELL SOUTH OF COLORADO...EXPECT ONLY SOME
MID AND HIGH LEVEL CLOUDINESS ALONG THE NM BORDER THROUGH
MONDAY...WITH VFR CONDITIONS TONIGHT AND TOMORROW OVER ALL THE
AREA.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

10/27