Hail in Colorado, August 27, 2002

SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO COLORADO
214 PM MDT TUE AUG 27 2002

...MAIN FORECAST CHALLENGE WILL BE LOCATION OF MCS DEVELOPMENT NEXT
COUPLE NIGHTS/RESULTING PCPN CHANCES...

LOW CLOUDS HAVE PERSISTED ALONG THE EAST SLOPES THROUGH EARLY
AFTERNOON WHICH HAS HAMPERED HEATING SO FAR.  MAIN OUTFLOW BOUNDARY
FROM LAST NIGHTS MCS IS STILL LOCATED ACROSS NE NM/TX PANHANDLE WITH
ANOTHER BOUNDARY FROM SECONDARY CONVECTIVE CLUSTER HAVING PUSHED
ACROSS LAS ANIMAS/BACA COUNTIES.  MAIN CHALLENGE TODAY WILL BE
CONVECTIVE INITIATION...WITH STRONG CAP STILL ACROSS SOUTHEAST
PLAINS (WHERE BEST CLEARING HAS TAKEN PLACE)...VS WEAKER CAP ALONG I-
25 CORRIDOR (WHERE CLOUD COVER HAS PERSISTED). LITTLE IN THE WAY OF
UPPER SUPPORT TO HELP FIRE OFF CONVECTION (EXCEPT ACROSS NE
COLORADO IN CLOSER PROXIMITY TO UPPER LEVEL JET)...SO WILL HAVE TO
RELY ON UPSLOPE/HEATING ALONE THIS AFTN. GENERALLY SCATTERED
POPS ALONG THE I-25 CORRIDOR LOOK GOOD...WITH LESSER POPS FURTHER
EAST. OVERNIGHT...LOW LEVEL JET ENHANCES ACROSS SOUTHEAST COLORADO...
WITH UPPER LEVEL DIVERGENCE ACROSS THE AREA...AND LOW LEVEL MOISTURE
FLUX DIV TO SUPPORT DEVELOPMENT OF MCS ACROSS EASTERN PLAINS.  AM
SOMEWHAT CONCERNED THAT MCS DEVELOPMENT WILL OCCUR FURTHER SOUTH
ALONG BOUNDARY ACROSS NE NM/NRN TX PANHNDLE LATER TONIGHT.
HOWEVER ANOTHER MCS MAY EVOLVE FROM NORTHEAST COLORADO
CONVECTION AND MOVE SOUTHWARD ACROSS ERN PLAINS. BROAD BRUSH 50 POPS
LOOK GOOD ACROSS FAR SOUTHEAST PLAINS OVERNIGHT...AND WILL MAKE
LITTLE CHANGES TO CURRENT GRIDS. AGAIN...SVR THREAT WILL BE PRESENT
WITH 40-50KT 0-6KM SHEARS...AND RESPECTABLE 1500-2000 J/KG OF
CAPE.

ON WEDNESDAY...AGAIN AFTER SOME MORNING STRATUS...SOUTHEAST PLAINS
WILL BREAK OUT BY AFTERNOON...WITH MESO-ETA/ETABUFR SOUNDINGS
SHOWING CONVECTIVE TEMPS IN THE MID 80S ACROSS THE SOUTHEAST
PLAINS.  UPPER JET OUT WEST MAY ALSO HELP INITIATE CONVECTION...AND
FINALLY SOME MID AND HIGH LEVEL MOISTURE INCREASES OVER THE WEST.
SO SLIGHT CHANCE POPS STILL LOOK WARRANTED THIS AREA.  ON THE
PLAINS...WILL PLAY THE GAME OF CAP BREAKING IN THE AFTN ALONG
EASTERN MTNS/ADJ PLAINS.  AGAIN 0-6KM SHEARS AROUND 40 KTS WITH
CAPES 1000-1500 J/KG.  THUS...SEVERE THUNDERSTORMS ARE AGAIN
POSSIBLE.  CONVECTION SHOULD EVOLVE INTO ANOTHER MCS.  AGAIN...
APPEARS TO BE 2 FOCUS AREAS...ONE ALONG THE MAIN SFC BOUNDARY
ACROSS NE NM/TX PANHDLE...WITH ANOTHER AREA ALONG PALMER DIVIDE
AND ACROSS THE EAST CEN PLAINS. WITH DETAILS STILL UNCERTAIN...WILL
BROAD BRUSH SCATTERED POPS ACROSS THE SOUTHEAST PLAINS...HIGHEST
ALONG THE CO/KS BORDER. OUT WEST...EXPECT ISOLATED HIGH BASED
CONVECTION TO DIE OFF DIURNALLY.

THURSDAY...SHORTWAVE OVER THE GREAT BASIN FINALLY LIFTS NORTHEAST
ACROSS FORECAST AREA ON THURSDAY.  AGAIN...LOTS OF LOW LEVEL
MOISTURE AROUND WITH DECENT SHEARS AND CAPES ACROSS SE PLAINS.  BEST
DYNAMICS WILL AGAIN BE ACROSS NORTHEAST COLORADO...AND NORTHERN
SECTIONS OF SOUTHEAST PLAINS.  HOWEVER WITH SOME DYNAMICS TO WORK
WITH...SCATTERED AFTERNOON THUNDERSTORMS LOOK PROBABLE MOST AREAS.
MOST OF THE MOISTURE WILL BE MID AND HIGH LEVEL ACROSS THE WRN MTN
AREAS...BUT WITH SHORTWAVE MOVING THROUGH ISOLATED MAINLY HIGH BASED
TSTORMS STILL LOOK GOOD.  TEMPERATURES WILL BE A CHALLENGE FOR
THURSDAY AS TIMING OF SHORTWAVE MAY CAUSE DRY LINE TO PUSH INTO EAST
PLAINS IN THE AFTERNOON...ALLOWING I-25 CORRIDOR TO WARM UP SOME.
WILL PLAY IT ON THE WARM SIDE OF GUIDANCE VALUES FOR NOW IN THESE
AREAS. THURSDAY NIGHT...AS SHORTWAVE MOVES THROUGH...THINK THAT
CONVECTION WILL SHIFT EASTWARD INTO KS OVERNIGHT WHERE LW LEVEL JET
AGAIN CRANKS UP. WINDS WILL ALSO INCREASE THURSDAY OVER THE HIGH
COUNTRY AS SHORTWAVE/UPPER JET MOVE ACROSS AREA...WHICH COULD BE A
CONCERN FOR FIRE WEATHER.

ON FRIDAY...AFTER THE SHORTWAVE PASSES...AVN KEEPS SOME HIGH BASED
MOISTURE OVER THE MTN AREAS...WITH ANOTHER UPPER JET MOVING INTO
NORTHWEST CO.  ETAX SHOWS SUBSTANTIAL DRYING ACROSS THE WRN MTN
AREAS...AND YESTERDAYS AVN RUN SUGGESTED SIMILAR SCENARIO.  THEREFORE
WILL PULL THE POPS ACROSS WRN AREAS. ACROSS THE SOUTHEAST PLAINS...
STILL SOME RESIDUAL LOW LEVEL MOISTURE...SO WILL KEEP IN SOME SLIGHT
CHANCE POPS FOR NOW.  BUT THESE TOO MAY NEED REMOVED...DEPENDING ON
POSITION OF DRY LINE.

ANOTHER UPPER TROUGH MOVES INTO THE WRN US THROUGH SUNDAY...WITH
SOUTHWEST FLOW RE-ESTABLISHING OVER THE AREA THROUGH THE EXTENDED.
AIR MASS OVER THE WRN MTN AREAS LOOKS TO BE FAIRLY DRY WITH PERIODS
OF MODEST MID AND HIGH LEVEL MOISTURE WORKING ITS WAY NORTHWARD
AROUND UPPER RIDGE TO OUR SOUTH.  THE SOUTHEAST PLAINS WILL LIKELY
RETURN TO A SIMILAR SET UP AS WHAT WEVE HAD IN RECENT DAYS...WITH
LOW LEVEL MOISTURE ACROSS THE PLAINS...AND CHANCES FOR THUNDERSTORMS
EACH DAY DEPENDING ON HEATING/STRENGTH OF CAP.  FOCUS FOR MCS
DEVELOPMENT WILL BE ALONG LOW LVL THETA-E AXIS ACROSS ERN CO/WRN
KS. SO SLIGHT CHANCE POPS EACH DAY LOOKS GOOD WITH LITTLE CHANGE IN
TEMPS.

.PUB...NONE.

KT