Severe Thunderstorm Warning 225, NWS Pueblo, CO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
330 PM MDT SUN AUG 15 2010

.SHORT TERM...

(TODAY AND TONIGHT)

CURRENTLY...STRATUS DECK OVER THE EASTERN PLAINS HAS BEEN SLOW TO
BREAK TODAY...AS MOST LOCATIONS ALONG AND EAST OF I-25 DIDN'T
SCATTER OUT UNTIL 20Z OR LATER. AS A RESULT...LATEST LAPS AND SPC
ANALYSIS SUGGEST FAIRLY LARGE (100-200 J/KG) CONVECTIVE INHIBITION
REMAINS IN PLACE EAST OF I-25. BEST INSTABILITY AT 21Z LIES IN A
NARROW BAND ALONG THE EASTERN MOUNTAINS AND NEAR THE NM
BORDER...WHERE CLOUDS BROKE EARLY AND TEMPERATURES HAVE WARMED INTO
THE 80S. FINALLY SEEING SOME DEEPER CONVECTION BREAK OUT ALONG THE
RATON MESA AND WEST OF KTAD...WHERE CAPES ARE AROUND 2000 J/KG.

TONIGHT...SOWDY1 HIGHLIGHTS MOST OF THE EASTERN MOUNTAINS AND
ADJACENT PLAINS FOR A SLIGHT RISK OF SEVERE THIS EVENING...THOUGH IT
MAY BE TOUGH TO GET MUCH MORE THAN ONE OR TWO PULSE SEVERE STORMS
AS STRONGEST 0-6 KM SHEAR LIES GENERALLY NORTH OF THE ARKANSAS RIVER
AND DEEPEST INSTABILITY WELL SOUTH. BEST CHANCE FOR SEVERE LOOKS TO
BE FROM PUEBLO SOUTHWARD WHERE INSTABILITY IS GREATEST...THOUGH IF
DEEPER CONVECTION CAN DEVELOP FARTHER NORTH...PALMER DIVIDE AREA
WOULD BE FAVORED. NAM AND GFS BOTH HINT AT SOME SORT OF MCS
DEVELOPING OVER THE SOUTHEAST PLAINS OVERNIGHT...AS TSRA BUILD
SOUTHEASTWARD ALONG THE MOISTURE AXIS AND STRENGTHENING LOW LEVEL
JET. MAIN CHANGES TO THE FORECAST WERE TO REDUCE POPS MOST AREAS
THIS EVENING GIVEN GREATER UNCERTAINTY...BUT KEPT AT LEAST CHANCE
POPS GOING THROUGH THE NIGHT EAST OF THE MOUNTAINS AS TSRA MAY LAST
THROUGH MUCH OF THE NIGHT ONCE AGAIN. REMOVED THE MENTION OF SEVERE
STORMS FROM THE GRIDS...AS AT THIS POINT SEVERE THREAT LOOKS
SOMEWHAT LIMITED.

MONDAY...WHAT LOOKED LIKE A CLEAR CUT SEVERE WEATHER DAY A COUPLE
DAYS AGO NOW LOOKS VERY MUDDLED...AS MODEL SURFACE FEATURES APPEAR
MUCH LESS FAVORABLE FOR STRONG STORMS. WILL LIKELY HAVE SOME STRATUS
OVER MUCH OF THE PLAINS EARLY MONDAY MORNING...THOUGH WITH
STRENGTHENING WESTERLY FLOW JUST ABOVE THE SURFACE...CLOUDS MAY MIX
OUT SLIGHTLY FASTER THAN THEY DID TODAY. BY AFTERNOON...BOTH NAM AND
GFS HAVE THE SURFACE WARM FRONT LIFTING NORTH OF THE PALMER
DIVIDE...WITH DRIER WEST/SOUTHWEST FLOW SPREADING OVER MUCH OF THE
EASTERN MOUNTAINS AND PLAINS. NAM IN PARTICULAR IS VERY
DRY...KEEPING ALMOST ALL OF SOUTHEAST COLORADO CONVECTION FREE
THROUGH THE AFTERNOON AS SURFACE DEWPOINTS FALL INTO THE
40S...LEADING TO RATHER PALTRY CAPES AROUND 500 J/KG. BEST DYNAMIC
LIFT APPEARS TO BE OVER NORTHERN COLORADO...AS SHORT WAVE TROUGH AND
UPPER JET LIFT OUT OF THE NORTHERN ROCKIES. COULD STILL SEE SOME
TSRA IF WE CAN HOLD ON TO HIGHER INSTABILITY LONGER THAN MODELS
INDICATE...WITH BEST CHANCES FOR STRONG/SEVERE CONVECTION NORTH OF A
KSPD TO KCOS LINE.  GIVEN THE UNCERTAINTY...HAVE BACKED OFF POPS
OVER THE EASTERN FOR MON AFTERNOON...AND WON'T MENTION SEVERE IN THE
ZONES. HAVEN'T TALKED MUCH ABOUT WESTERN MOUNTAIN ZONES...THOUGH IT
APPEARS AREA OF DEEPER MOISTURE AND CONVECTION OVER NM WILL LIFT
INTO THE SAN JUANS MON AFTERNOON...LEADING TO AN UPTURN IN TSRA
COVERAGE THROUGH MUCH OF THE DAY.  --PETERSEN

.LONG TERM...

(MONDAY NIGHT THROUGH SUNDAY)

MONDAY NIGHT-TUESDAY NIGHT...MODERATE WESTERLY FLOW PROGGED ACROSS THE
REGION MONDAY NIGHT BECOMES MORE NORTHWEST AND DECREASES THROUGH THE
DAY TUESDAY AS AN EMBEDDED SHORT WAVE MOVING ACROSS THE ROCKIES
MONDAY NIGHT CONTINUES INTO THE NORTHERN AND CENTRAL HIGH PLAINS
INTO TUESDAY AND UPPER LEVEL RIDGING ACROSS DESERT SW SLOWLY BUILDS
INTO THE GREAT BASIN REGION. MODELS HAVING A DIFFICULT TIME PINNING
DOWN LOCATION OF PASSING WAVE WITH THE NAM A TAD FURTHER SOUTH WITH
ASSOCIATED JET CORE MOVING ACROSS THE CENTRAL ROCKIES WHEREAS THE
GFS AND ECMWF ARE FURTHER NORTH KEEPING LARGE SCALE ASCENT WITH
THE RIGHT REAR QUAD OF THE JET MOVING ACROSS THE SOUTH CENTRAL AND
SOUTHEAST COLORADO MONDAY NIGHT. AT ANY RATE...HAVE STAYED CLOSER TO
THE GFS SOLUTION AND HAVE KEPT SCATTERED TO LOW END LIKELY POPS
ACROSS THE AREA THROUGH THE EVENING WITH BEST POPS ACROSS THE FAR SE
PLAINS WHERE MODELS DO HAVE EVENING CONVECTION DEVELOPING INTO AN
MCS WHICH ROLLS INTO WESTERN KANSAS THROUGH EARLY TUESDAY MORNING.
WITH THE LARGE SCALE LIFT MOVING ACROSS THE AREA...COULD SEE STRONG
TO SEVERE STORMS PRODUCING LARGE HAIL AND GUSTY WINDS ACROSS THE
EASTERN PLAINS THROUGH THE LATE EVENING. COULD SEE SOME STRATUS
ACROSS THE EASTERN PLAINS EARLY TUESDAY MORNING...THOUGH WITH
WESTERLY DOWNSLOPE FLOW AND DEVELOPING SUBSIDENCE BEHIND WAVE...IT
SHOULD BE FAIRLY PATCHY. WITH SLIGHTLY COOLER...DRIER AND MORE
SUBSIDENT NORTHWEST FLOW BEHIND WAVE ON TUESDAY...SHOULD SEE
ISOLATED AT BEST LATE AFTERNOON AND EARLY EVENING STORMS...WITH BEST
COVERAGE ACROSS THE EASTERN MTS AND IMMEDIATE ADJACENT PLAINS WITH
ENHANCED LOW LEVEL UPSLOPE FLOW.

WEDNESDAY-FRIDAY...UPPER LEVEL RIDGING ACROSS THE DESERT SW AND
GREAT BASIN REGION BUILDS INTO WESTERN COLORADO ON WEDNESDAY AND
FLATTENS ACROSS THE STATE THROUGH THURSDAY NIGHT AS ANOTHER
SHORTWAVE MOVING ONSHORE ACROSS THE WEST COAST CONTINUES TO MOVE
ACROSS THE ROCKIES AND INTO THE HIGH PLAINS THURSDAY NIGHT.
LONGER RANGE MODELS BEGIN TO DIFFER THURSDAY NIGHT WITH THE GFS
CONTINUING TO INDICATE ANOTHER EMBEDDED SHORT WAVE MOVING ACROSS
GREAT BASIN THURSDAY NIGHT AND ACROSS THE STATE ON FRIDAY...WHERE
AS THE LATEST ECMWF DOES NOT INDICATE THE SECONDARY SYSTEM AND IS
PROGGING WARMER AND DRIER CONDITIONS ACROSS THE STATE WITH THE
RIDGE REBUILDING INTO WESTERN COLORADO. AT ANY RATE...SHOULD SEE
INCREASING CHANCES OF PRECIP FROM WEST TO EAST WEDNESDAY NIGHT AND
THURSDAY AS MOISTURE AN UVV INCREASES AHEAD OF EMBEDDED WAVE
MOVING ACROSS THE REGION. I STARTED TO LOWER POPS ACROSS THE AREA
ON FRIDAY...KEEPING ISOLATED TO SCATTERED POPS WITH BEST COVERAGE
ACROSS THE HIGHER TERRAIN...THOUGH LATER SHIFT MAY NEED TO CONTINUE
TO LOWER IF LATEST ECMWF SOLUTION IS MORE CORRECT. AS FOR TEMPS...WITH
WARMING ALOFT AND DOWNSLOPE FLOW...SHOULD SEE HIGHS WARMING TO ABOVE
SEASONAL AVERAGES WEDNESDAY AND THURSDAY...ESPECIALLY ACROSS THE
PLAINS WITH SLIGHT COOLING FOR FRIDAY.

SATURDAY-SUNDAY...MODELS IN DECENT AGREEMENT OF UPPER LEVEL RIDGING
ACROSS WESTERN COLORADO SLOWLY BUILDING INTO THE EASTERN HALF OF THE
STATE...WITH A SLOW INCREASE IN AVAILABLE MOISTURE IN DEVELOPING SW
FLOW ALOFT ACROSS WESTERN COLORADO THROUGH SUNDAY. WITH THAT
SAID...WILL SEE TEMPERATURES WARMING BACK TO ABOVE SEASONAL AVERAGES
THROUGH THE WEEKEND WITH ISOLATED DIURNAL HIGH BASED STORMS
POSSIBLE...ESPECIALLY ACROSS THE HIGHER TERRAIN. -MW

&&

.AVIATION...ANOTHER CHANCE OF SCT TSRA THIS EVENING...MAINLY OVER
THE EASTERN MOUNTAINS AND PLAINS. COULD SEE A VCTS VCNTY OF KALS
THROUGH ABOUT 01Z...WHILE WINDOW FOR TSRA AT KPUB AND KCOS IS FROM
23Z-04Z. CONVECTION WILL PERSIST OVERNIGHT ACROSS THE PLAINS...WITH
MORE LOW CLOUDS AND AREAS OF IFR STRATUS AT KPUB AND KCOS THROUGH
MID MORNING MONDAY.

&&

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

10/23