Severe Thunderstorm Warning 155, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
313 PM CDT SAT JUL 7 2001

...FCST CHALLENGE THRU FCST PD WILL BE CHC FOR NOCTURNAL MCS NEXT
TWO NIGHTS...

18Z SFC ANALYSIS INDICATED A STATIONARY FRONT NEAR OLU TO JUST NORTH
OF MCK. A WARM FRONT TO ITS SOUTH OVER NW KS TO ALONG THE NEBR AND
KS BORDER. DWPTS REMAIN IN THE 60S FROM THE PNHDLE INTO THE LOWER
70S FROM SC INTO ERN NEBR. WV IMAGERY INDICATED A DISTINCT SHORTWAVE
TROUGH FROM NE UT INTO NW CO KICKING OFF EARLY AFTN CONVECTION NEAR
LARAMIE WY TO FORT COLLINS COLORADO. THIS WILL BE A MAJOR PLAYER IN
EVENTUALLY MCS DEVELOPMENT TONIGHT MAINLY OVER THE NORTHERN CWFA.
LAST NIGHT MCS NOT HANDLED WELL BY THE ETA BUT THE AVN DID FCST
THIS.

MODEL CHOICE WILL BE A BLEND OF THE ETA AND AVN AS THE AVN
INDICATING AN MCS TONIGHT OVER NRN NEBR WHILE THE ETA INDICATED ONE
SUNDAY NIGHT.

TONIGHT...CONVECTION OVER ERN WY AND NORTHEAST COLORADO SHOULD
DEVELOP INTO AN MCS OVERNIGHT AS IT RUNS THE PERIPHERY OF THE UPPER
RIDGE. CHANCES REMAIN LOW OVER THE SERN ZONES AS CORFIDI VECTORS
POINT CONVECTION TO THE ENE AND 0-6KM BULK SHEAR MAG OF 35 TO 40 KTS
RESIDE NORTH OF THIS AREA.

SUNDAY...WEATHER PATTERN REMAINS NEARLY THE SAME AS THE FRONTAL
BOUNDARY REMAINS JUST THE OUR SOUTHEAST AND DWPTS REMAIN IN THE 60S
TO AROUND 70. AFTER MORNING SHOWERS AND THUNDERSTORMS END OVER THE
NORTHEAST...WILL BE PARTLY TO MOSTLY SUNNY HIGHS SHOULD WARM TO
AROUND 90S NORTH AND 95 TO 100 FAR SOUTHEAST. WILL KEEP A 20 POP FOR
THE NWRN ZONES AS H85 THETA-E RIDGE AXIS EXTENDS ACROSS CENTRAL NEBR
INTO SW SD AND CIN VALUES ARE LOW.

SUNDAY NIGHT...THE AVN IS NOT RESOLVING ANY SIGNIFICANT VORT MAXES
INTO NEBR. THE ETA HOWEVER INDICATES A STRENGTHENING VORT AS IT
BREAKS THE CREST OF THE RIDGE OVER NRN WY AND WRN SD AND DIVES
SOUTHEAST. ALTHOUGH CONFIDENCE IS LOWER WILL CARRY 40 POPS NORTH.

MONDAY...AS UPPER RIDGE CENTER DROPS SOUTH INTO THE TX PNHDLE AND
HIGH PRESSURE FROM THE NORTHERN PLAINS SETTLES SOUTH...HIGHS WILL
COOL TO THE MID 80S NORTH TO 90 TO 95 FAR SOUTH.

MONDAY NIGHT...A H7 TEMPS COOL TO 8 TO 10C BY 12Z TUE...CHC FOR
CONVECTION ANYWHERE ACROSS THE CWFA. BEST FOCUS HOWEVER WILL BE
ALONG THE WESTERN ZONES AND NORTHERN ZONES WHERE VORT MAXES ROTATE
AROUND THE UPPER FLOW.

EXTENDED...THE MRF INDICATED A SLOW RETROGRADE OF THE UPPER HIGH
CENTER WSW FROM THE TX PNHDL 12Z TUESDAY TO EASTERN AZ BY 00Z SUN.
THIS SHOULD GIVE CWFA A SLIGHT CHC OF NOCTURNAL MCS CHCS ALONG THE
PERIPHERY OF UPPER RIDGE TUESDAY AND WEDNESDAY. IN ADDITION THE H7
TEMPS COOL TO 8C TO 12C RANGE. DRY AND A SLIGHT COOLDOWN THU AND FRI
TO 85 TO 95 AND 80S FOR SAT. CONFIDENCE LOW HOWEVER ON THIS FCST
MOVEMENT AS CANADIAN MODEL INDICATES RIDGE FLATTENS SOUTH INTO TX
WHILE THE 06 12Z RUN OF THE ECMWF KEEPS THE UPPER RIDGE LOCKED OVER
KS-CO.

.LBF...NONE.

ROBERG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
1016 PM CDT SAT JUL 7 2001

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1010 PM    6 NW ANTIOCH              NE   .75 INCH HAIL
07/07/01   SHERIDAN

RLB