FXUS65 KPUB 032115
AFDPUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
215 PM MST THU DEC 3 2009
.SHORT TERM...
(TONIGHT AND FRIDAY)
CURRENTLY...THE UPPER LOW WAS CONTINUING TO SLOWLY MOVE TO THE SE
ACROSS MN AND IA THU AFTN...AND WAS FINALLY SWINGING THE TROUGH AXIS
ACROSS THE SE CORNER OF COLORADO. LIGHT SNOW HAS BEEN PERSISTENT
ALONG PORTIONS OF THE I25 CORRIDOR TODAY...BUT IS GRADUALLY COMING
TO AN END AT MOST SPOTS. IN ADDITION...LOW CLOUDS AND SNOW NEVER
MADE IT OVER THE SANGRES INTO THE VALLEY. AS WAS EXPECTED...TEMPS
HAVE REMAINED NEARLY STEADY AND VERY COLD TODAY...LOWER TO MID 20S
FOR MOST LOCATIONS SAVE FOR ALONG THE I25 CORRIDOR WHERE TEMPS
RANGED FROM12 TO 19F.
TONIGHT...MODELS AGREE ON THE TROUGH AXIS EXITING THE STATE...AND
COLD BUT DRY NORTHERLY FLOW THEN SETTLING IN OVERNIGHT. DECIDED TO
KEEP ISOLATED POPS OVER THE S SANGRES AND S FOOTHILLS JUST FOR
TONIGHT...SINCE THIS WILL BE THE AREA OF MOST LIKELIHOOD...BUT THERE
IS THE POTENTIAL FOR THE NEXT SHIFT TO COMPLETELY NIL THE POP GRIDS
SINCE THERE IS SOME QUESTION ON HOW LONG THE LIGHT SNOW WILL HANG
ON. OTHERWISE...CLEARING SKIES TONIGHT AND ONCE AGAIN A VERY COLD
NIGHT WITH MOST LOCATIONS SEEING MIN TEMPS IN THE NEGATIVES.
TOMORROW...NW FLOW ALOFT SETTLES IN AS TEMPS WARM BY ABOUT 8C AT
BOTH 700 AND 850 MB. HOWEVER...FEEL IT WILL BE A SLOW WARM UP
CONSIDERING HOW COLD IT WILL BE TO START OFF. WENT WITH THE LOWER
END OF NUMERICAL GUIDANCE. DRY CONDITIONS ARE EXPECTED. MOORE
.LONG TERM...
(SAT-THU)
... CONTINUED BRRRRRRRRRR WITH SOME SNOW ...
LONG RANGE MODELS IN FAIRLY GOOD AGREEMENT...ALBEIT THERE IS SOME
AMPLIFICATION ISSUES BY MID WEEK WEEK NEXT WEEK.
FIRST...FRIDAY NIGHT (00Z-12Z SAT)...ANOTHER COLD NIGHT IN STORE.
COLDEST TEMPS LIKELY IN THE MTN VALLEYS WHERE EXCELLENT RADIATIONAL
COOLING SHOULD ALLOW TEMPS TO GO WELL BELOW ZERO. PLAINS WILL ALSO
BE COLD WITH SINGLE DIGITS AND LOWER TEEN VALUES WIDESPREAD.
FOR SATURDAY...STRONG ZONAL FLOW WILL BE OVER AREA...HOWEVER I DO
NOT THINK WE ARE GOING TO WARM UP MUCH ON THE PLAINS...
I.E...DOWNSLOPE FLOW WILL NOT BE A FACTOR. NEXT IN A SERIES OF
SHORTWAVES/ARCTIC SURGES WILL BE TO OUR NORTH AND WEST...AND WITH
THE FORCING TO THE WEST AND LEE TROUGHING OVER THE SE
PLAINS...EXPECT SFC WINDS OVER THE PLAINS TO BE RATHER LIGHT. THIS
IN TURN WILL NOT ALLOW FOR THE COLD AIR TO SCOUR OUT OF THE REGION.
LIKEWISE...WENT MORE IN LINE WITH THE GFS TEMP GUIDANCE.
SPEAKING OF ARCTIC AIR...THE NEW SURGE SHOULD BE COMING DOWN THE
PLAINS DURING THE AFTERNOON AND EXPECT THE COLDER AIR TO BE OVER THE
REGION BY LATE AFTERNOON. COLD AIR MAY ACTUALLY COME DOWN IN TWO
SEPARATE SURGES...ONE DURING THE AFTERNOON AND THE 2ND DURING THE
EARLY EVENING. LIKEWISE...HIGH TEMPS ON SAT WILL LIKELY OCCUR IN THE
LATE MORNING OR VERY EARLY AFTERNOON TIME PD.
AS COLD AIR FILTERS IN...LOWER ATMOS WILL SATURATE ONCE AGAIN ON THE
PLAINS. EXPECT SKIES TO CLOUD UP BY MID TO LATE EVENING HOWEVER IT
SHOULD REMAIN DRY MOST OF THE NIGHT. OVER THE MTNS...EXPECT SNOW
SHOWERS TO BE ON THE INCREASE SAT EVENING.
SUNDAY WILL BE COLD AND CLOUDY EVERYWHERE. SNOW WILL BE LIKELY
ACROSS THE REGION...ESPECIALLY NORTH OF HIGHWAY 50 AS THE BEST
FORCING ALOFT MOVES OVER THE N 1/2 OF THE STATE. SEVERAL INCHES OF
SNOW WILL BE POSSIBLE ACROSS THE C MTNS WITH 1-2" ACROSS N EL PASO
COUNTY AND 1-4" ACROSS THE PIKES PEAK REGION.
AFTER THE 1ST SHORT WAVE GOES BY...THE 2ND ONE WILL BE RIGHT ON ITS
HEELS. THIS 2ND SHORTWAVE WILL HAVE A LOT MORE MID AND UPPER LVL
MOISTURE WITH IT SO EXPECT A MORE SIGNIFICANT SNOWFALL TO OCCUR
ACROSS THE MTNS STARTING MONDAY AND LASTING INTO TUESDAY. AS FOR THE
PLAINS...THINGS ARE A BIT MORE IFFY. AS MENTIONED ABOVE...THERE IS
SOME MODEL INDESCREPANCIES WITH THIS 2ND SYSTEM AS BOTH THE EC AND
GFS MOVE IT ACROSS TUESDAY...BUT THE GFS IS MUCH MORE AMPLIFIED. IF
THE GFS VERIFIES THEN THE PLAINS WILL HAVE A GOOD CHANCE OF
ACCUMULATING SNOW ON TUESDAY...HOWEVER IF THE EC VERIFIES...THEN
THE BUSINESS END OF THE SYSTEM WILL BE FARTHER NORTH...AND THE SE CO
PLAINS WILL ONLY SEE A SURGE OF COLDER AIR COMING IN. LOOKING AT THE
GFS ENSEMBLES...IT APPEARS THAT THE OPERATIONAL RUN MAY BE A BIT TOO
AMPLIFIED AND THE EC MAY BE THE MODEL OF CHOICE.
NO MATTER WHAT...ANOTHER SURGE OF ARCTIC AIR WILL MOVE ACROSS THE
REGION TUESDAY. TUESDAY NIGHT COULD BE VERY COLD ACROSS ALL OF
SOUTHERN COLORADO.
&&
.AVIATION...
KALS...VFR CONDITIONS EXPECTED THE NEXT 24 HRS.
KCOS...MVFR CONDITIONS POSSIBLE THIS EVENING THROUGH 02Z...THEN VFR.
THERE IS THE OUTSIDE CHANCE OF GROUND FOG DEVELOPING...BUT WITH
DRIER AIR MOVING IN WILL HOLD OFF ON FORECASTING THE REDUCED VSBYS.
KPUB...VFR CONDITIONS THE NEXT 24 HRS...BUT THE SAME CHANCE FOR
GROUND FOG REDUCING VSBYS...AND WILL BRIEF INCOMING SHIFT TO WATCH
FOR THIS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
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