Severe Thunderstorm Warning 199, NWS Hastings, NE

SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
337 PM CDT THU JUL 3 2003

...FORECAST CHALLENGES REVOLVE AROUND WARM TEMPS AND DELINEATION OF
RAIN/T-STORM CHANCES OVER THE NEXT SEVERAL DAYS...

UPPER AIR DATA ANALYSIS IN CONJUNCTION WITH WATER VAPOR IMAGERY
FEATURES PERSISTENT UPPER RIDGE FROM THE DESERT SOUTHWEST TO THE
NORTHERN PLAINS...WHILE SHORTWAVE TROUGH AND ASSOCIATED HEIGHT
FALLS SPREAD INTO THE NORTHERN ROCKIES/CANADIAN PRAIRIES.

18Z SURFACE ANALYSIS REVEALS CONFLUENCE AXIS EXTENDING FROM ALONG
I-80 IN SCNTRL NEB EASTWARD INTO SOUTHWEST IOWA...WHILE LEE TROUGH
ORIENTED N/S FROM WESTERN NEBRASKA INTO EASTERN COLORADO. FURTHER
UPSTREAM...COLD FRONT ACROSS NORTHERN/WESTERN SOUTH DAKOTA MAKING A
GRADUAL APPROACH TOWARD THE AREA.

INITIAL CONCERN IS FOR TSTM CHANCES TONIGHT. ANY ISOLD TSTM
PROSPECTS THIS EVENING WILL LIKELY BE RELEGATED TO WESTERN/NCNTRL NEB
-- AND POSSIBLY INTO THE N/W FRINGE OF THE CWA -- GIVEN STRONG
INHIBITION AND FACT THAT COLD FRONT IS STILL WELL N/W OF THE CWA. IN
A RELATIVE SENSE...A LITTLE BETTER CHANCE COMES TO THE AREA LATE
TONIGHT...MAINLY FOR THE NORTHERN HALF OF THE CWA...AS THE COLD FRONT
APPROACHES. OTHERWISE...LOW TEMPERATURES TONIGHT SIMILAR TO NIGHTS
PREVIOUS.

PROVIDED DEVELOPMENT OCCURS LATE TONIGHT...COULD BE A FEW LEFTOVER
TSTMS DURING THE DAY ON FRIDAY...HOWEVER BULK OF THE MORNING/
AFTERNOON SHOULD BE RAIN-FREE. ANOTHER CONCERN WILL BE THE HEAT...
ALTHOUGH TEMPERATURES SHOULD BE A FEW DEGREES COOLER GIVEN SOME
ADDITIONAL CLOUD COVER AND EXPECTED PASSAGE OF FRONT FOR AT LEAST
THE NORTHWEST PORTION OF THE CWA. AS SUCH...HEAT INDICES SHOULD BE
MARGINAL AS TO NOT NECESSITATE AN ADVISORY.

COLD FRONT/TROUGH WILL GRADUALLY SLIDE SOUTHWARD ON FRIDAY...LIKELY
ORIENTED SOMEWHERE ALONG THE I-80 CORRIDOR BY LATE AFTERNOON/EARLY
EVENING. 12Z ETA SUGGESTS 3000-3500 MLCAPES AS NEAR 70 DEWPOINTS POOL
IN THE VICINITY OF THE FRONT. DEEP LAYER SHEAR ON THE ORDER OF 30-40
KTS WOULD BE SUFFICIENT FOR ORGANIZED SEVERE STORMS. ASSOCIATED
THREAT OF LARGE HAIL AND DAMAGING WINDS WOULD BE POSSIBLE WITH ANY
DEVELOPMENT -- TORNADO PROSPECTS SHOULD BE MINIMAL GIVEN DEEPLY MIXED
ENVIRONMENT. NATURALLY WITH SUCH A WARM AIRMASS ALOFT...KEY QUESTION
BECOMES COVERAGE/TIMING OF SUCH ACTIVITY. IN SPITE OF INHIBITION/WARM
TEMPS ALOFT...LFCS ARE REACHABLE...AS STRONG FRONTOGENETICAL FORCING
SHOULD BE SUFFICIENT FOR ISOLD TO SCATTERED TSTM DEVELOPMENT BY THE
LATE AFTERNOON AND EVENING HOURS. BOTH 12Z OPERATIONAL ETA BMJ SCHEME
AND ETA KAIN-FRITSCH SUGGEST CONVECTIVE SIGNAL BY THE 00Z/03Z
TIMEFRAME.

FRONTAL BOUNDARY WILL MEANDER ACROSS THE REGION THROUGH THE
WEEKEND...MAINTAINING AT LEAST SLIGHT -- MAINLY AFTERNOON/
NIGHTTIME -- TSTM CHANCES.

IN THE EXTENDED...ENSEMBLE CONSENSUS SUGGESTS SECONDARY SHORTWAVE
TROUGH TO MOVE THROUGH THE NORTHERN PLAINS ON SUNDAY/MONDAY...WITH
LOW AMPLITUDE WESTERLIES ACROSS THE NORTHERN TIER THEREAFTER. AS
SUCH...TSTM CHANCES REMAIN IN PLACE THROUGH EARLY NEXT WEEK...WITH
DRY/NEAR NORMAL TEMPERATURE PATTERN FOR MID WEEK.

.GID...NONE.

GUYER

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-041200-

HAZARDOUS WEATHER OUTLOOK...CORRECTED TYPO
NATIONAL WEATHER SERVICE HASTINGS NE
300 PM CDT THU JUL 3 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL NEBRASKA AND
PARTS OF NORTH CENTRAL KANSAS.

.DAY ONE...TODAY AND TONIGHT

THERE WILL BE A SLIGHT CHANCE FOR ISOLATED THUNDERSTORMS TO DEVELOP
THIS EVENING...GENERALLY NORTH OF A GOTHENBURG TO KEARNEY LINE AND
NEAR SURFACE A TROUGH THAT STRETCHES FROM NORTHEASTERN TO
SOUTHWESTERN NEBRASKA. ADDITIONAL SCATTERED THUNDERSTORMS WILL BE
POSSIBLE AHEAD OF A COOL FRONT ADVANCING SOUTHEAST OUT OF THE DAKOTAS
INTO NORTHERN NEBRASKA AFTER MIDNIGHT. A FEW OF THESE STORMS COULD BE
STRONG OR SEVERE...ESPECIALLY NORTH OF A LOUP CITY TO YORK LINE. THE
PRIMARY HAZARD IS LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE COOL FRONT WILL SLOW DOWN OVER SOUTH CENTRAL NEBRASKA EARLY
FRIDAY...STALLING NEAR THE KANSAS BORDER BY LATE AFTERNOON. THIS
FRONTAL BOUNDARY...TOGETHER WITH AN OUTFLOW BOUNDARY FROM EARLY
MORNING THUNDERSTORMS MOVING EAST INTO IOWA...AND A WEAK UPPER LEVEL
DISTURBANCE...WILL HELP FOCUS THUNDERSTORM DEVELOPMENT ONCE AGAIN BY
EARLY AFTERNOON...LASTING INTO THE EVENING. A FEW OF THESE STORMS
COULD ALSO BECOME STRONG OR SEVERE. CHANCES FOR THUNDERSTORMS WILL
REMAIN POSSIBLE...ALTHOUGH ON AN ISOLATED BASIS...THROUGH MONDAY...
WITH GENERALLY DRY WEATHER FORECAST FROM TUESDAY ON OUT.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT DUE
TO ISOLATED SEVERE WEATHER POTENTIAL.

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