Severe Thunderstorm Warning 71, NWS Goodland, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
853 PM MDT FRI MAY 23 2003

UPDATED FORECAST WILL BE ISSUED SHORTLY TO LOWER POPS IN THE
SOUTHWEST BASED ON LATEST SAT/RADAR TRENDS FURTHER NORTH. KEPT
LIKELY ACROSS THE NORTHEAST AREAS...ALSO REMOVED WIND/HEAVY RAIN
WORDING AND LEFT PATCHY FOG. ADJUSTED TEMPERATURE/DEWPOINT GRIDS TO
FIT LATEST OBSERVATIONS...EVERYTHING ELSE APPEARS ON TRACK.

PREVIOUS DISCUSSION BELOW:
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TONIGHT...VARIOUS PARAMETERS AGAIN LOOK QUITE FAVORABLE FOR NUMEROUS
THUNDERSTORMS...FROM MID EVENING ON. ABUNDANT LOW LEVEL MOISTURE IN
PLACE PER REGIONAL 12Z SOUNDINGS WITH PRECIPITABLE WATER FROM
130-160 PERCENT OF NORMAL. PRONOUNCED LOW/MID LEVEL THETA-E RIDGE
AXII WILL EXTEND FROM THE TX/OK PANHANDLES INTO NORTHEAST CO THIS
EVENING. EXPECT PRIMARY THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON
NORTHWEST OF OUR ZONES IN A LOW LEVEL CONVERGENCE AXIS.
MITIGATING/LIMITING FACTORS FOR CONVECTIVE INITIATION ARE THE
APPARENT LACK OF SHORTWAVES AND LIMITED HEATING DUE TO SLOW
DISSIPATION OF CLOUD COVER ALONG MOISTURE FEED. HOWEVER...BASED ON
BOTH ETA/GFS...BELIEVE THUNDERSTORMS WILL BECOME MORE NUMEROUS AS
THEY PROPAGATE SOUTHEAST INTO THE INSTABILITY AXIS ACROSS OUR ZONES
THIS EVENING. SHEAR PARAMETERS/CAPES/SOUNDING PROFILES LOOK
FAVORABLE FOR SOME SEVERE STORMS WITH EVENING 850 MB WINDS SOUTHEAST
AT 20 KTS...VEERING TO NORTHWEST AT 35 KTS AT 500 MB. BASED ON MODEL
SIGNALS...EXPECT ANOTHER MESOSCALE CONVECTIVE SYSTEM (MCS) ACROSS
WESTERN KS TO DEVELOP...LARGER IN AREAL EXTENT THAN THIS MORNING/S.
PREFER HIGHER RAIN CHANCES ON ETA VERSUS NGM/GFS ..AND WILL GO WITH
70 PERCENT POPS (PROBABILITY OF PRECIPITATION) AREAWIDE.

SAT...WILL LIKELY SEE SOME LEFTOVER THUNDERSTORMS IN THE MORNING
ACROSS THE SOUTHERN ZONES. LOW/MID LEVEL THETA-E ADVECTION FIELDS
INDICATE DRYING/STABILIZING THEREAFTER ACROSS OUR ZONES. WITH
EXPECTED CLOUD COVER...LACK OF FORCING AND NEGATIVE THETA-E ADVECTION
...NO THUNDERSTORMS EXPECTED IN THE AFTERNOON WITH THETA-E RIDGE
AXIS TRANSLATING WEST/SOUTH OF OUR ZONES. COOLER GUIDANCE HIGHS LOOK
BEST BASED ON CLOUD COVER.

SAT NIGHT/SUN...LOW LEVEL UPSLOPE PRODUCES OVERCAST LOW CLOUDS SAT
NIGHT. MAY SEE A FEW THUNDERSTORMS ACROSS THE SOUTHWEST ZONES SAT
NIGHT BUT STEERING WINDS LOOK UNFAVORABLE...THUS WILL KEEP IT DRY.
ON SUNDAY...LARGE AMPLITUDE RIDGE PREVAILS ACROSS THE ROCKIES WITH
LOW LEVEL SOUTHEAST FLOW ACROSS THE TRI STATE AREA (EAST CENTRAL CO/
NW KS/SW NEB). WITH LOW/MID LEVEL THETA=E RIDGE AXIS HUGGING THE CO
FRONT RANGE...NO THUNDERSTORMS EXPECTED IN OUR ZONES.
HOWEVER...SHOULD SEE CLOUDS HANG ON MUCH OF THE DAY WITH NEAR
SEASONAL MAXIMA.

MEMORIAL DAY...WE/LL BE CAUGHT IN THE TUG OF WAR BETWEEN THE ROCKIES
UPPER RIDGE AND THE UPPER TROUGH TO OUR EAST. LOW LEVEL UPSLOPE AND
WEAK STEERING FLOW ALOFT WILL KEEP THUNDERSTORMS CONFINED WEST OF
OUR ZONES...SO IT WILL BE DRY FOR OUTDOOR ENTHUSIASTS AND
ACTIVITIES. WILL TREND BELOW GFS MAXIMA BASED ON PROJECTED 850 MB
TEMPERATURES AND EXPECTED CLOUD COVER.

TUE...NORTHERLY FLOW ALOFT WITH LOW LEVEL SOUTHEAST UPSLOPE WILL
KEEP THUNDERSTORMS WEST OF OUR ZONES. GFS HIGHS LOOK GOOD BASED ON
850 MB TEMPERATURES AND CLOUD COVER.

WED/THU/FRI...23/00Z GFS RUN NOW MORE IN LINE WITH 21/00Z RUN
KEEPING STRONG RIDGING ACROSS THE ROCKIES AND WESTERN HIGH PLAINS...
AS OPPOSED TO THE 22/00Z RUN WHICH BROKE DOWN THE RIDGE TOO FAST.
SHOULD SEE A DECENT WARMING TREND ON WED AS LOW LEVEL WINDS BECOME
DOWNSLOPE ALLOWING WARM TEMPERATURES ALOFT TO MIX DOWN. THU/FRI LOOK
QUITE WARM WITH STRONG UPPER RIDGING AND PROJECTED 850 MB
TEMPERATURES. GFS HIGHS LOOK TOO COLD THU/FRI.

.GLD...NONE.

SR

COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-241200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GOODLAND KS
1044 AM MDT FRI MAY 23 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHWEST KANSAS...EXTREME
SOUTHWEST NEBRASKA...AND EAST CENTRAL COLORADO.

.DAY ONE...TODAY AND TONIGHT

THE AIR MASS OVER THE TRI-STATE AREA WILL REMAIN MOIST THIS
AFTERNOON AND TONIGHT. ALTHOUGH LOW CLOUDS AND FOG HAVE INHIBITED
SURFACE HEATING...THE CLOUDS WILL DISSIPATE FROM WEST TO EAST THIS
AFTERNOON. THIS WILL ALLOW ADEQUATE SURFACE HEATING TO OCCUR...
RESULTING IN AN UNSTABLE AIR MASS AFTER 3 PM MDT (4 PM CDT).
VERTICAL WIND PROFILES WILL BECOME INCREASINGLY FAVORABLE FOR SEVERE
WEATHER AFTER 3 PM MDT (4 PM CDT). THE COMBINATION OF INSTABILITY
WITH FAVORABLE WIND SHEAR AND UPSLOPE SURFACE WINDS WILL PRODUCE
SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. THE BEST
CHANCE OF SEVERE WEATHER WILL OCCUR WEST OF A TRENTON NEBRASKA TO
LEOTI KANSAS LINE AFTER 6 PM MDT (7 PM CDT) THIS EVENING. THE MAIN
THREAT WILL BE LARGE HAIL...BUT WIND GUSTS TO 70 MPH AND ISOLATED
TORNADOES MAY ALSO OCCUR.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THE MOIST AND UNSTABLE AIR MASS WILL CONTINUE OVER THE AREA
SATURDAY. THUNDERSTORMS AGAIN WILL BE POSSIBLE DURING THE AFTERNOON
AND NIGHT. HIGH PRESSURE WILL MOVE OVER THE HIGH PLAINS SUNDAY
BRINING DRY WEATHER THROUGH THURSDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE LIKELY THIS AFTERNOON AND TONIGHT.

MENTZER

KSZ001>004-013>016-028-029-241200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GOODLAND KS
1142 PM MDT FRI MAY 23 2003

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR PORTIONS OF NORTHWEST KANSAS UNTIL 6 AM MDT (7 AM CDT) THIS
MORNING. THE WATCH INCLUDES THE FOLLOWING COUNTIES:

IN KANSAS...CHEYENNE...SHERMAN...RAWLINS...THOMAS...LOGAN...
DECATUR...SHERIDAN...GOVE...NORTON...AND GRAHAM.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

MWM