Severe Thunderstorm Warning 284, NWS Goodland, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
238 PM MDT MON SEP 4 2000

...FORECAST CONCERN WL BE TEMPS...

BASED ON INITIAL ANALYSIS...CURRENT TRENDS...AND SATL...WL PREFER A
BLEND OF THE ETA/AVN. RATHER DEEP/COLD TROF ALG WEST COAST. BASED ON
AMPLIFIED PATTERN/STRONGER JET WINDS...LIKE THE SLOWER EASTWARD
PROGRESSION OF THE TROF THAT THE AVN DEPICTS. AVN HAS HANDLED THIS TROF THE
BEST FROM THE BEGINNING. FRONT BACKING IN FROM THE EAST WAS FIRST
CAUGHT BY NGM/AVN YDA WITH ETA NOW CATCHING UP AND HANDLING IT
PRETTY WELL.

BACKDOOR FRONT IS MAKING GOOD PROGRESS TWD WEST...AND BASED ON
PRESSURE RISES AND POSN OF 85H/SFC HIGH...FRONT SHOULD BACK INTO THE
CWFA. HOW FAR WEST IT GOES REMAINS THE QUESTION WHICH MAKES FOR A
MESSY TEMP FCST...AND WIDE VARIABILITY IN MAXES ON TUE. ALSO...FRONT
AT SOME POINT HAS TO MOVE BACK TO THE EAST AS SYSTEM AND A NEW FRONT
PUSHES IN FROM THE WEST. SO ON WEDNESDAY...HOW FAST DOES THE COLD
AIR MIX OUT.

ATTM...AM GOING TO EXPECT BACKDOOR FRONT TO MAKE IT INTO THE NE HALF
OF THE CWFA BY TMRW MRNG. WL HAVE CUT BACK CURRENT MAXES
DRAMATICALLY WITH WRN PTN BEING THE WARMEST...AND WL GO NR/SLIGHTLY
BLO GUIDANCE EAST TO NR TO SLIGHTLY ABV GUIDANCE WEST. SINCE AVN IS
DOING BETTER AT MID/UPR LVLS WITH TROF OUT WEST...LIKE ITS SLOWER
ARRIVAL OF FRONT FROM THE WEST ON WEDNESDAY. ATTM AM EXPECTING COOL
AIR TO MIX OUT FROM WEST TO EAST ON WED WITH TEMPS NR TO SLIGHTLY
ABV TUE MAXES. WL BE GOING NEAR TO ABV GUIDANCE.

NOW FOR PCPN CHANCES. FOR TONIGHT...LOOKS TO BE A WEAK RRQ OF 25H
JET NR ERN CWFA. ALSO WEAK S/W MOVES ACROSS...HAVE BNDRY PUSHING IN
FROM EAST...AND HAVE BEST MSTR OVR NRN AND ERN AREAS. WL GO ISOLD IN
NW PTN AND 20 PERCENT IN THE EAST. AFTER THAT THE MID/UPR LVL MSTR
CLEARS OUT SO WL HAVE NO TSRA TMRW AND TMRW NIGHT. WL PUT IN A
SLIGHT CHC IN NW PTN OF CWFA ON WED AFTN AS FRONT APROACHES...AND
DYNAMICS/COOLER AIR ALOFT MOVE IN.

IN THE EXTENDED...MEDIUM RANGE MODELS CONTINUE TO HAVE A ROUGH TIME
IN CURRENT SYNOPTIC FLOW PATTERN. MODELS CONTINUE TO MOVE BACK AND
FORTH BETWEEN SPEEDING UP TROF/WEAKENING SRN CONUS RIDGE AND SLOWING
DOWN/AMPLIFYING THE PATTERN. NOT ONLY HAVE THE MODELS FLIP FLOPPED
BUT THEY ALSO DISAGREE WITH EACH OTHER. SO SUFFICE TO SAY CONFIDENCE
IN THE EFP IS LOW.

CURRENT SYNOPTIC PATTERN IS FOR THE MEAN TROF POSITIONS ALG EACH
COAST WITH THE RIDGE IN THE CENTER. CURRENT JET ANALYSIS/PROGS ALONG
WITH SATL WOULD INDICATE PATTERN TO STAY FAIRLY AMPLIFIED ALTHOUGH
IT IS TRENDING TOWARD BEING LESS AMPLIFIED BY END OF THE FCST
PERIOD. HOWEVER THE MEAN POSITIONS REMAIN UNCHANGED. BASED ON THE
ABV...I LIKE A BLEND OF THE UKMET/MRF/AVN.

THE MRF MAY BE A LTL TOO AMPLIFIED AT CERTAIN POINTS WITH ECMWF
BEING THE MOST PROGRESSIVE. THE UKMET FOR A LOT THE TIME STAYS
BETWEEN THOSE TWO SOLNS. THINK THAT ECMWF IS TOO PROGRESSIVE GIVEN
ABV REASONING PLUS ITS TENDENCY THE LAST THREE DAYS TO BREAK 50H
RIDGE DOWN TOO QUICKLY. HWVR ITS TREND HAS BEEN TO RAISE HEIGHTS A
LTL EACH NEW RUN. CURRENT EFP APPEARS REASONABLE...AND WL MAKE NO
MAJOR CHANGES. WITH SFC BOUNDARY...DYNAMICS...AND MSTR PLUME
REMAINING NEAR AREA...WL KEEP CHC OF TSRA THROUGH SAT.

.GLD...NONE.

BULLER