Severe Thunderstorm Warning 231, NWS Hastings, NE

SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
230 AM CDT FRI AUG 23 2002

LOTS OF ITEMS ON THE AGENDA TODAY...INCLUDING REMNANTS OF SMALL MCS
NOW WORKING ACROSS WESTERN CWFA...CONTINUED DEVELOPMENT OF STORMS
NEAR EASTERN CWFA BORDER...AND FINALLY THE POTENTIAL FOR A SOMEWHAT
WIDESPREAD RAIN EVENT LATE TONIGHT AND SATURDAY.

HEAVY RAINFALL IN EASTERN NEBRASKA JUST OFF THE KUEX SCOPE...IN AREA
OF MASSIVE MOISTURE...LLJ...UPPER RRQ OF JET STREAK AND MASS
DIFFLUENCE PER EVENING ANALYSIS. STUFF MOVING IN FROM THE WEST WON/T
DIE. INFLOW APPEARS WEAK...AND STORMS SHOULD BECOME MORE ELEVATED
BEHIND SURFACE BOUNDARY AND OUTFLOWS GENERATED. NONE-THE-LESS...A
CONTINUED CHANCE FOR RAIN THIS MORNING FOR THE THE CWFA WILL BE
INCLUDED. HARD TO ALIGN JUST YET...AND WILL WHAT TIL THE LAST MINUTE
FOR SOME FINAL CARVING. SHORTWAVE RIDGING WILL SET UP BY LATE
MORNING LEAVING SUNSHINE THIS AFTERNOON. MINOR FLY IN THE OINTMENT
WILL BE DEVELOPING LOW CLOUDS AND FOG DEVELOPING NORTHEAST ZONES.
THESE SHOULD DISSIPATE WITH SUBSIDENCE IN WAKE OF THE DECAYING
MCS.

REGARDING LATE FRIDAY NIGHT THROUGH SATURDAY NIGHT. IF MODEL
CONTINUITY IS THE CHOICE...THEN ITS GOING TO RAIN. THIS IS A STRONG
STATEMENT GIVEN IT SEEMS TO RAIN EVERYWHERE BUT HERE THIS SUMMER...
BUT NO MATTER THE MODEL (CANADIAN/EC/NOGAPS/K-F/ETA/NGM/AVN) LIFT AND
RESULTING QPF IS GENERATED FOR THE TIME FRAME ACROSS THE CWFA.

THE DETAILS REVEAL A STRONG SOUTHERN JET UPWARDS OF 90KTS WILL KNIFE
THROUGH GREAT BASIN...LEAVING WESTERN NEBRASKA IN A FAVORABLE LFQ
POSITION. MASS DIVERGENCE SETS UP ACROSS AS FLOW IS PROGGED TO BE
STRONGLY DIFFLUENT IN THE SANDHILLS DURING THE DAY. ANOTHER HARD TO
PEG SHORTWAVE WILL KICK OUT BY MORNING...AS LINGERING LLJ OF 30+
KNOTS CONTINUES EARLY IN THE DAY. MOISTURE MAY NOT BE AS PLENTIFULLY
WIDESPREAD AS TONIGHT...BUT NARROW AXIS OF 8C H7 DEWPOINTS TO
WESTERN KANSAS AND CORRESPONDING H85 AXIS YIELDS A 2+ INCH
PRECIPITABLE H20 VERY NEAR THE CWFA (FAVORING SSW SECTIONS). LACK OF
STRONG SURFACE BOUNDARY LIKE TONIGHT MAY ALSO BE A NEGATIVE...BUT
LARGE SCALE LIFT WILL OVERCOME THE SHORTCOMINGS...AS EVENT HAS
GOOD ELEVATED THERMAL FORCING. LAPSE RATES ARE MOIST ADIABATIC OR
LESS EASTERN ZONES...AND MARGINALLY SEVERE WEST. MODELS DROP THIS ONE
OFF THE CLIFF INTO THE MOIST AXIS RIGHT AWAY...BUT CORFIDI VECTORS
AND THICKNESS PARAMETERS SUGGEST SOME INITIAL EASTWARD MOVEMENT
BEFORE TURNING. THE DECISION IS TO THE INCREASE POPS BEGINNING LATE
FRIDAY NIGHT IN THE NORTHWEST...AND CONTINUE CWFA-WIDE SATURDAY. BEST
CHANCE SATURDAY EVENING WILL BE SOUTHEAST ZONES BEFORE JET STREAK
SLIPS NORTH AND SHORTWAVE RIDGING TAKES HOLD. HPC RAINFALL PROGS
BANKING ON THINGS PICKING UP AROUND HERE LATE TONIGHT AND SATURDAY AS
WELL. LOOKS LIKE WERE ALL ALONG THE SAME LINE OF THOUGHT ATTM.

RIDGING SUNDAY SHOULD LEAD TO A DRY DAY...AND THAT TREND LOOKS TO
CONTINUE MUCH OF THE WEEK. OUTSIDE SHOT FOR RAIN LATE WEDNESDAY...BUT
NOT WORTHY OF CHANGES RIGHT NOW. TEMPERATURES WILL BE SEASONAL FOR
THIS TIME OF YEAR.

.GID...NONE.

MORITZ

NEZ039>041-046>049-060>064-072>077-082>087-230330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HASTINGS NE
1000 PM CDT THU AUG 22 2002

...SEVERE THUNDERSTORM WATCH NUMBER 628 IS NO LONGER IN EFFECT FOR
CENTRAL AND SOUTH CENTRAL NEBRASKA...

ALTHOUGH ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
OVERNIGHT...NO WIDESPREAD SEVERE WEATHER IS ANTICIPATED. HENCE...
THE SEVERE THUNDERSTORM WATCH PREVIOUSLY IN EFFECT UNTIL 10 PM
HAS BEEN ALLOWED TO EXPIRE.

GURNEY