Tornadoes and Hail in Kansas, May 20, 2001

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE DODGE CITY KS
315 PM CDT SUN MAY 20 2001

THIS MORNINGS UPPER AIR ANALYSIS SHOWING 25H 130KT JET EXTENDING
ACROSS W CANADA INTO NW CONUS WITH LEFT EXIT REGION OVER ERN MT.
140M HT FALLS NOTED IN MONTANA AND ONLY WEAK HT RISES PRESENT ALONG
THE COAST OF WA/OR/NRN CA. 7H-5H DEFORMATION ZONE STILL PRODUCING
SOME PCPN OVER CWA AS IT HAS BEEN SLOWLY WORKING ITS WAY EASTWARD AS
TONIGHTS COLD FRONT MOVES SOUTH ACROSS WY/WRN NE. STILL APPEARS SOME
GOOD CAA CONTINUES TO ADVECT INTO THE BASE THE UPPER LVL TROF OVER
THE NORTHERN ROCKIES WHICH SUGGESTS THIS SYSTEM WILL CONTINUE TO DIG
SOUTH. ALL MODELS THIS MORNING APPEARED TO HAVE A DECENT HANDLE WITH
THIS SYSTEM AND TIMING SHOWS OVERNIGHT PASSAGE ACROSS WESTERN KANSAS
ROUGHTLY BETWEEN 02 AND 06Z.

ALTHOUGH ATMOSPHERE AT THIS TIME APPEARS TO BE DRYING OUT BEHIND THE
PREFRONTAL TROF WHICH WAS LOCATED JUST EAST OF DDC AND HYS AT 19Z,
IT DOES APPEAR THAT SOME MOISTURE IS PRESENT AHEAD OF THE S/W TROF
WHICH WAS CURRENTLY CROSSING EASTERN WY. ALSO NOTED WERE THE CAPE
VALUES VIA SPC HOURLY MESO ANALYSIS SITE WHICH WERE BETWEEN
2000-3000 IN WESTERN KS. KCYS RADAR LOOP HAS BEEN SHOWING PCPN HAS
BEEN INCREASING IN AREAL COVERAGE EARLY THIS AFTERNOON. WITH THIS IN
MIND, PROGGED LAPSE RATES TONIGHT AHEAD OF THE FRONT AND A FAIRLY
IMPRESSIVE VORT LOBE CROSSING WESTERN KANSAS WILL KEEP LIKELY POPS
GOING WITH FROPA.

STILL A FAIRLY TIGHT SFC GRADIENT PRESENT BEHIND THE FRONT, HOWEVER
WINDS BEHIND THE FRONT NOT AS STRONG AS ANTICIPATED YESTERDAY. STILL
GIVEN THE S/W TROF WAS STILL APPROACHING THE AREA, STRONG SUBSIDENCE
BEHIND THE COLD FRONT AND A TIGHTENING SFC GRADIENT BY 06Z...WINDS
SPEEDS SHOULD REACH ADV CRITERIA FOR A COUPLE OF HOURS. WILL
THEREFORE ISSUE A WIND ADVISORY FOR TONIGHT FOR THE ENTIRE CWA.

MONDAY THE SFC FRONT PROGGED TO BE WELL INTO OK WITH SFC HIGH
PRESSURE BEGINNING TO BUILD INTO THE CENTRAL PLAINS. WITH THE 5H
COLD POOL OVER NRN KS AND CYCLONIC FLOW ALOFT, SHOULD SEE SOME
CLOUDS AND POSSIBLY AN ISOLATED LATE DAY SHRA UNDER THE COLD POOL
WHERE LAPSE RATES RANGE FROM 6.5 TO 7.5 NEAR THE HYS AREA AT 18Z
MON. HOWEVER MOISTURE LOOKS SOMEWHAT LIMITED, SO WILL ONLY GO WITH
PARTLY CLOUDY CONDITIONS IN THE EAST AND MOSTLY SUNNY IN THE WEST.
WITH SFC HIGH SETTLING WILL ALSO DECREASE THE WIND THROUGH THE DAY.

SFC HIGH BUILDS ACROSS WESTERN KANSAS INTO TX/OK BY 12Z TUESDAY.
WINDS LIGHT AND DWPTS PROGGED IN THE 30S. SO GIVEN CLEAR SKIES AND
LIGHT WINDS WILL HAVE TO LEAN TOWARDS THE COOLER MAV NUMBERS FOR
LOWS MONDAY NIGHT.

ON TUESDAY THE UPPER LVL TROF BEGINS TO SHIFT TO THE EAST WITH
RIDGING BEGINNING OVER THE ROCKIES. AVN/ETA HOWEVER HINTING AT A
WEAK VORT LOBE ROTATING AROUND THE UPPER LOW WHICH APPEARS TO BE
LOCATED OVER MI/IA EARLY TUESDAY. WITH THIS IN MIND, MAY SEE A FEW
MORE CLOUDS ON TUESDAY AS WELL AS A SLOWER WARMUP THAN WHAT THE FWC
SUGGEST. STILL WILL BUMP TEMPS UP BUT GO COOLER THAN THE FWC NUMBERS
AT THIS TIME.

EXTENDED DISCUSSION...
DRY FORECAST TO CONTINUE THROUGH EXTENDED PERIOD AS UPPER TROUGH NOW
DIGGING INTO THE CENTRAL CONUS MOVES EAST INTO THE OHIO VALLEY BY
MIDWEEK AND THEN LIFTS OUT TOWARD NEXT WEEKEND.  TEMPERATURES WILL
CONTINUE AT OR BELOW SEASONAL NORMS THROUGH MUCH OF THE PERIOD AS
NORTHERLY FLOW CONTINUES.  MRF STILL POINTING TO A VORT LOBE
ROTATING AROUND THE UPPER LOW SOUTH ACROSS THE CENTRAL PLAINS
WEDNESDAY NIGHT AND THURSDAY.  SHOULD SEE A REINFORCING SHOT OF
COOLER AIR WITH THIS FEATURE AND WILL HOLD TEMPERATURES IN THE 60S
ON THURSDAY AS A RESULT.  TEMPERATURES SHOULD SLOWLY WARM TOWARD
NEXT WEEKEND AS THE UPPER SYSTEM MOVES OUT AND UPPER LEVEL RIDGING
MOVES IN FROM THE WEST.

IN THE 8 TO 10 DAY PERIOD, MRF SHOWING A SIMILAR SOLUTION TO
YESTERDAYS RUN IN DIGGING ANOTHER UPPER TROUGH INTO THE WESTERN
STATES WITH THE CENTRAL PLAINS RIDGE MOVING OUT.  THINK THAT EARLY
PART OF THE OUTLOOK PERIOD WILL PROBABLY BE DRY WITH ABOVE NORMAL
TEMPERATURES BUT CHANCES FOR THUNDERSTORMS WILL INCREASE TOWARD THE
END OF THAT PERIOD AS UPPER FLOW BACKS TO THE SOUTHWEST AND THE GULF
OPENS UP.

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE
CONTAINED WITHIN THE DODGE CITY ZONE FORECAST.

DDC 043/058 038/068 042 700
GCK 042/059 037/068 042 700
EHA 039/060 040/068 045 600
LBL 043/058 039/068 043 700
HYS 037/055 035/064 040 6-0
P28 045/060 040/068 042 7-0

.DDC...WIND ADVISORY FOR THE ENTIRE CWA.
KSZ030-031-043>046-061>066-074>081-084>090

RB/GERARD